Thyroid Thyroid GlandGland

Prof. Dr. Mohamed Prof. Dr. Mohamed Ahmed YehiaAhmed Yehia Professor of general Professor of general surgerysurgery Zagazig Faculty Of Zagazig Faculty Of MedicineMedicine

Anatomy of thyroid glandAnatomy of thyroid gland Weight : 15 – 25 gm Weight : 15 – 25 gm Shape : Butterfly , consisting of two lobes connected by an isthmus. The Shape : Butterfly , consisting of two lobes connected by an isthmus. The pyramidal lobe is projection extends up wards from left border of thepyramidal lobe is projection extends up wards from left border of the isthmus isthmus Extension : - Upper pole which extends to the middle of thyroid cartilage .Extension : - Upper pole which extends to the middle of thyroid cartilage . - Lower pole which extends to the 5th tracheal ring. - Lower pole which extends to the 5th tracheal ring. Capsule : The thyroid gland has two capsules :Capsule : The thyroid gland has two capsules :

True capsule from condensation of its connective tissueTrue capsule from condensation of its connective tissue False capsule from pretracheal fascia. False capsule from pretracheal fascia.

Relations : Relations : Anteriorly :Anteriorly : Skin , SC. fat , platysma , deep cervical fascia, Skin , SC. fat , platysma , deep cervical fascia,

pretracheal muscles :-pretracheal muscles :- Omo hyoid muscle .Omo hyoid muscle . Sterno hyoid muscle. Sterno hyoid muscle. Sterno thyroid muscle. Sterno thyroid muscle. Its lower poles is overlapped by sterno mastoid muscle.Its lower poles is overlapped by sterno mastoid muscle.

Posteriorly : Posteriorly : Two tubes ( trachea , esophagus)Two tubes ( trachea , esophagus) Two cartilages ( thyroid , cricoid )Two cartilages ( thyroid , cricoid ) Two muscles (Cricothyroid , inf. Constrictor of the pharynx)Two muscles (Cricothyroid , inf. Constrictor of the pharynx) Two nerves ( recurrent – external laryngeal )Two nerves ( recurrent – external laryngeal )

Blood supply :Blood supply : It is high vascular organ It is high vascular organ Arterial :Arterial : 5 5

Superior thyroid artery from external Superior thyroid artery from external carotid arterycarotid artery

Inferior thyroid artery from Inferior thyroid artery from thyrocervical trunk of subclavian thyrocervical trunk of subclavian artery.artery.

Thyrodima artery from innominate Thyrodima artery from innominate Venous :Venous : 6 6 Sup. thyroid vein Sup. thyroid vein Drain into Drain into

internal jugular vein. internal jugular vein. Middle thyroid vein Middle thyroid vein

Inferior thyroid vein Drains into Inferior thyroid vein Drains into innominate vein.innominate vein.

NervesNerves relatedrelated to the glandto the gland : :

1- The Superior laryngeal nerves.1- The Superior laryngeal nerves.2- The Recurrent laryngeal nerves.2- The Recurrent laryngeal nerves.

1- The Superior laryngeal nerves :1- The Superior laryngeal nerves : (branch. of the vagus)(branch. of the vagus) Divides into two branches : Divides into two branches : a) Internal laryngeal nerve, which pierces (with sup. a) Internal laryngeal nerve, which pierces (with sup.

laryngeal art.) the thyrohyoid membrane to the larynx.laryngeal art.) the thyrohyoid membrane to the larynx. It is sensory to larynx above the level of vocal cordsIt is sensory to larynx above the level of vocal cords b) The external laryngeal nerve, which descends with b) The external laryngeal nerve, which descends with

the sup. thyroid art. the sup. thyroid art. It is motor to the cricothyroid muscle.It is motor to the cricothyroid muscle.

2-2- The Recurrent laryngeal nervesThe Recurrent laryngeal nerves : : ( branches ( branches of vagi )of vagi ) In the early fetus the neck is divided into 6 branchial In the early fetus the neck is divided into 6 branchial

arches each contains an arches each contains an aortic arch.aortic arch. the recurrent laryngeal nerve is the nerve of the 6th the recurrent laryngeal nerve is the nerve of the 6th

branchial arch which gives rise to the developing branchial arch which gives rise to the developing larynx.larynx.

As the neck elongates and the heart descends, the As the neck elongates and the heart descends, the recurrent laryngeal nerves are dragged downward by recurrent laryngeal nerves are dragged downward by the descending aortic arches. the descending aortic arches.

On the Rt. side the 5th & 6th arches disappear On the Rt. side the 5th & 6th arches disappear leaving the Rt. R.L.N. to hook around the 4th arch leaving the Rt. R.L.N. to hook around the 4th arch =Rt. subclavian artery.=Rt. subclavian artery.

On the Lt. side R.L.N. remains hooking around the On the Lt. side R.L.N. remains hooking around the 6th arch, which doesn`t disappear but forms the 6th arch, which doesn`t disappear but forms the ductus arterious which later gives ligamentum. ductus arterious which later gives ligamentum. Arteriouses which is overlapped by the aortic arch. Arteriouses which is overlapped by the aortic arch.

So So The Lt. one hooks around the aortic then The Lt. one hooks around the aortic then

ascendsascends The Rt. one hooks around the Rt. subclavian The Rt. one hooks around the Rt. subclavian

art. then ascends.art. then ascends. Both of them ascends in the trachea-esophageal Both of them ascends in the trachea-esophageal

groove to enter larynx JUST behind the groove to enter larynx JUST behind the suspensory ligament of berry ( anatomical suspensory ligament of berry ( anatomical landmark for recurrent laryngeal nerve ) landmark for recurrent laryngeal nerve )

The recurrent nerves are motor to all intrinsic The recurrent nerves are motor to all intrinsic muscles of larynx and sensory to the larynx muscles of larynx and sensory to the larynx below the level of vocal cords.below the level of vocal cords.

Lymphatics :Lymphatics : Into the near by deep cervical Into the near by deep cervical lymph nodeslymph nodes

Surgical important Surgical important pointspoints Thyroid gland is one of sites of Thyroid gland is one of sites of occultoccult carcinoma in the body carcinoma in the body

The thyroid gland moves up and down during deglutition because it is The thyroid gland moves up and down during deglutition because it is enclosed in the pretracheal fascia "enclosed in the pretracheal fascia "false capsulefalse capsule""""surgical capsulesurgical capsule"which is "which is attached to the ligament of berry " suspensory ligament" which attached to attached to the ligament of berry " suspensory ligament" which attached to the tracheal and thyroid cartilage.the tracheal and thyroid cartilage.

The middle thyroid veinThe middle thyroid vein must be ligated first, as it`s easily ruptures with must be ligated first, as it`s easily ruptures with massive hemorrhage which may be mask the surgical field.massive hemorrhage which may be mask the surgical field.

TheThe Superior Thyroid ArterySuperior Thyroid Artery must be ligated within the gland to avoid must be ligated within the gland to avoid injury of injury of superior laryngeal nervesuperior laryngeal nerve which leads to : which leads to :

- Choking : due to loss of sensation above level of vocal cords. (I.L.N)- Choking : due to loss of sensation above level of vocal cords. (I.L.N) - Loss of high pitched voice due to paralysis of erico-thyroid M. (E.L.N)- Loss of high pitched voice due to paralysis of erico-thyroid M. (E.L.N) The Inferior Thyroid ArteryThe Inferior Thyroid Artery must be ligated away and lateral to the must be ligated away and lateral to the

gland to avoid injury of recurrent nerve and parathyroid glands gland to avoid injury of recurrent nerve and parathyroid glands The infrahyoid musclesThe infrahyoid muscles must be divided ( in thyrodectomy for big or must be divided ( in thyrodectomy for big or

malignant gland) near their upper end to avoid injury of its nerves which malignant gland) near their upper end to avoid injury of its nerves which comes from below ( from ansacervicalis)comes from below ( from ansacervicalis)

InIn Near Total ThyroidectomyNear Total Thyroidectomy we must leave post medial part of the we must leave post medial part of the gland to avoid injury of parathyroid glands and recurrent nerves.gland to avoid injury of parathyroid glands and recurrent nerves.

In thyroidectomyIn thyroidectomy we have to put a drain before closure of the skin to we have to put a drain before closure of the skin to avoid post operative hematoma.avoid post operative hematoma.

In unilateral recurrent nerve injury :In unilateral recurrent nerve injury : vocal cord on that side becomes motionless so the vocal cord on that side becomes motionless so the

voice is weak and hoarseness is usually improve within voice is weak and hoarseness is usually improve within weeksweeks

In bilateral recurrent injuryIn bilateral recurrent injury : : IncompleteIncomplete : : Leads to adduction of cords and Leads to adduction of cords and

suffocationsuffocation so, tracheostomy must be done so, tracheostomy must be done

immediately.immediately. CompleteComplete : : Leads to aphonia as the cord lie Leads to aphonia as the cord lie

mid waymid way between adduction and abduction between adduction and abduction

inin cadaveric position.cadaveric position. Complete removal or devascularization of the four Complete removal or devascularization of the four parathyroidparathyroid

glands leading to glands leading to TetanyTetany

Development of thyroid Development of thyroid glandgland

The thyroid gland develops as a The thyroid gland develops as a median downgrowth of a column of median downgrowth of a column of cells from the pharyngeal floor cells from the pharyngeal floor between the 1st and the 2nd between the 1st and the 2nd pharyngeal pouch (subsequently pharyngeal pouch (subsequently marked by marked by thethe foramen caecumforamen caecum of of the tongue). The canalized column the tongue). The canalized column becomes the thyroglossal duct. The becomes the thyroglossal duct. The thyroglossal duct forms the thyroglossal duct forms the pyramidal lobe, the isthmus and pyramidal lobe, the isthmus and most of lateral lobes of the thyroid. most of lateral lobes of the thyroid. Its remnant may appear in adult as :Its remnant may appear in adult as :

Thyroglossal cystThyroglossal cyst or or thyroglossal thyroglossal fistulafistula or or ectopic thyroid.ectopic thyroid.

Thyroglossal CystThyroglossal Cyst It may occur at any site along the course of the thyroglossal duct. It It may occur at any site along the course of the thyroglossal duct. It

is considered to be one type of tubulodermoids. It may occur above is considered to be one type of tubulodermoids. It may occur above the hyoid bone (suprahyoid) but it is more commonly found below the hyoid bone (suprahyoid) but it is more commonly found below it (infrahyoid). it (infrahyoid).

It has the following characters : It has the following characters : Exactly in the middle line (in 25% of cases it may be shifted to one Exactly in the middle line (in 25% of cases it may be shifted to one

side , usually to the left) - Shape side , usually to the left) - Shape globular .globular . - Surface - Surface smooth .smooth . - Consistency - Consistency firm .firm . Moves with deglutition and protrusion of the tongue.Moves with deglutition and protrusion of the tongue. A fibrous band can usually be felt extending from the cyst upwards A fibrous band can usually be felt extending from the cyst upwards

towards the tongue. towards the tongue. Attached to deep structures but not to the skin unless infection has Attached to deep structures but not to the skin unless infection has

occurred.occurred. Treatment Treatment :: Excision and dissection of the tract Excision and dissection of the tract “Sistrunk’s “Sistrunk’s

operationoperation”. The thyroglossal cyst must be excised because infection ”. The thyroglossal cyst must be excised because infection is inevitable due to fact that the wall contains nodules of lymphatic is inevitable due to fact that the wall contains nodules of lymphatic tissue which communicate by lymphatics of lymph nodes of the tissue which communicate by lymphatics of lymph nodes of the neck. neck.

It is never congenital , always It is never congenital , always acquiredacquired due to infection or due to infection or incision of pre-existing cyst. It appears as a tiny opening in incision of pre-existing cyst. It appears as a tiny opening in the middle line of the neck discharging serous fluid or the middle line of the neck discharging serous fluid or purulent mucoid material. The opening moves up with purulent mucoid material. The opening moves up with deglutition and protrusion of the tongue and becomes deglutition and protrusion of the tongue and becomes inverted inwardinverted inward due to uneven rates of growth of the neck due to uneven rates of growth of the neck as a whole and that of the thyroglossal tract. The tract can as a whole and that of the thyroglossal tract. The tract can be felt as a fibrous band extending upwards from the fistula. be felt as a fibrous band extending upwards from the fistula. It is adherent to hyoid bone and may even pass through it.It is adherent to hyoid bone and may even pass through it.

TreatmentTreatment :: excision of the whole tract up to the base of the excision of the whole tract up to the base of the tongue. In order to avoid the recurrence the middle portion tongue. In order to avoid the recurrence the middle portion of hyoid bone must be excised.of hyoid bone must be excised.

Multiple transverse incisions in the neck the first enclosing Multiple transverse incisions in the neck the first enclosing the opening of the fistula and dissection proceeds upwards the opening of the fistula and dissection proceeds upwards as for as possible. Another incision may done following the as for as possible. Another incision may done following the tract upwards “tract upwards “Sistrunk’s operationSistrunk’s operation”. Unless the fistula is ”. Unless the fistula is completely removed recurrence is inevitable. completely removed recurrence is inevitable.

Thyroglossal Fistula " Sinus"

Ectopic thyroid tissue may occur anywhere along the course of the Ectopic thyroid tissue may occur anywhere along the course of the thyroglossal tact. The comment site is the point of origin of the thyroid at thyroglossal tact. The comment site is the point of origin of the thyroid at the base of tongue or foramen cecum (lingual , cervical intro thoracic)the base of tongue or foramen cecum (lingual , cervical intro thoracic)

The lingual thyroid appears as a firm nodule dating from birth and may The lingual thyroid appears as a firm nodule dating from birth and may increase in size during menstruation If it is big it may interfere with increase in size during menstruation If it is big it may interfere with swallowing , speaking and breathing. Ulceration and bleeding may be swallowing , speaking and breathing. Ulceration and bleeding may be caused by trauma caused by trauma

TreatmentTreatment : :excision , excision , butbut , before excision one must be sure of , before excision one must be sure of the presence of the normal thyroid in the neck thyroid tissue present in the presence of the normal thyroid in the neck thyroid tissue present in the body this can be achieved by : the body this can be achieved by :

Radio – active iodine uptake.Radio – active iodine uptake. Surgical exploration of the neck.Surgical exploration of the neck.

The lateral aberrant thyroidThe lateral aberrant thyroid Thyroid tissue to be ectopic in nature but it is now considered to Thyroid tissue to be ectopic in nature but it is now considered to

be secondaries in the lymph gland from a small papillferous be secondaries in the lymph gland from a small papillferous cacinoma of the thyroid.cacinoma of the thyroid.

Ectopic Thyroid

RetrosternalRetrosternal GoitreGoitre A very few retrosternal goitres arise from ectopic thyroid T. but , most arise from A very few retrosternal goitres arise from ectopic thyroid T. but , most arise from

the lower pole of nodular goitre. If the neck is short and pretracheal muscles are the lower pole of nodular goitre. If the neck is short and pretracheal muscles are strong as in men , intrathoracil pressure tends to draw these nodules into superior strong as in men , intrathoracil pressure tends to draw these nodules into superior mediastinum. mediastinum.

The degree of descent :The degree of descent : Substernal type :Substernal type : when nodule is palpable. when nodule is palpable.plunging type :plunging type : when intrathoracic goitre is forced into the neck by increased intra when intrathoracic goitre is forced into the neck by increased intra

thoracic pressure.thoracic pressure.Intra thoracic type :Intra thoracic type : Clinical Features Clinical Features It may be symptomless or produce severe obstructive symptoms : It may be symptomless or produce severe obstructive symptoms : Dyspnea particularly at night / cough "brassy cough" which is spasmodicDyspnea particularly at night / cough "brassy cough" which is spasmodic with stridor. with stridor. Engorgement of neck veins : in severe cases sup. veins on chest wall.Engorgement of neck veins : in severe cases sup. veins on chest wall. Dysphagia rare (Recurrent N. paralysis) Dysphagia rare (Recurrent N. paralysis) It also may be malignant or toxic.It also may be malignant or toxic.Investigation Investigation X.Ray (AP and lat. View) : soft T. shadow in the sup. mediastinum ,sometimes with X.Ray (AP and lat. View) : soft T. shadow in the sup. mediastinum ,sometimes with

calcification, Deviation or compression of trachea.calcification, Deviation or compression of trachea. I3 scan : may help to distinguish a retrosternal goitre from a mediastinal tumor.I3 scan : may help to distinguish a retrosternal goitre from a mediastinal tumor.Treatment :Treatment : if obstructive symptoms are present, it is unwise to treat a retrosternal if obstructive symptoms are present, it is unwise to treat a retrosternal

goitre with anti-thyroid drugs or radio iodine as these may enlarge the goitre so goitre with anti-thyroid drugs or radio iodine as these may enlarge the goitre so resection must done and carried out from the neck.resection must done and carried out from the neck.

Struma ovariiStruma ovarii It is not ectopic , but port of an ovarian teratoma very It is not ectopic , but port of an ovarian teratoma very

rarely carcinogenic change occurs or hyperthyroidism rarely carcinogenic change occurs or hyperthyroidism develops.develops.

It is a congenital deficiency of thyroid function which It is a congenital deficiency of thyroid function which may be associated with aplasia of the thyroid or with a may be associated with aplasia of the thyroid or with a goitrous gland cretinoid goitre.goitrous gland cretinoid goitre.

ClinicallyClinically The child is sluggish , constipated, puffy face, thick The child is sluggish , constipated, puffy face, thick

lips , flattened nose, protruding tongue , short neck lips , flattened nose, protruding tongue , short neck and thick short hand (spade shaped hands). He rare and thick short hand (spade shaped hands). He rare cries , and learn to suck , walk, talk and control of the cries , and learn to suck , walk, talk and control of the sphincters much later than normal.sphincters much later than normal.

In adolescence , the pat is dwarfed and mentally In adolescence , the pat is dwarfed and mentally retarded with dry wrinkled skin , supraclavicular pads retarded with dry wrinkled skin , supraclavicular pads of fat delayed epiphyseal ossification and very low of fat delayed epiphyseal ossification and very low B.M.R.B.M.R.

Treatment :Treatment : Thyroid extract should be given for life. In continued Thyroid extract should be given for life. In continued

goitre partial thyroidectomy is indicated to reduce goitre partial thyroidectomy is indicated to reduce the size of the swelling.the size of the swelling.

Cretinism

GoitersGoiters"" guttur guttur = = throatthroat" " definitiondefinition : : Any enlargement of thyroid glandAny enlargement of thyroid gland clinical diagnosesclinical diagnoses : : mass in the anatomical site of thyroid gland mass in the anatomical site of thyroid gland and moves up and down with deglutition.and moves up and down with deglutition.

PhysiologyPhysiology - The circulating inorganic iodine is picked up to the thyroid cells and- The circulating inorganic iodine is picked up to the thyroid cells and oxidation occurs by peroxidase enzyme forming oxidized iodineoxidation occurs by peroxidase enzyme forming oxidized iodine - This oxidized iodine bind to tyrosine forming mono and- This oxidized iodine bind to tyrosine forming mono and di-iodotyrosine by the iodonase enzyme. di-iodotyrosine by the iodonase enzyme. - Coupling of mono iodotyrosine and di-iodotyrosine occurs forming- Coupling of mono iodotyrosine and di-iodotyrosine occurs forming tri-iodotyrosine T3 and two molecules of di-iodotyrosine formingtri-iodotyrosine T3 and two molecules of di-iodotyrosine forming tetra-iodotyrosine T4 which stored in the thyroid follicles .tetra-iodotyrosine T4 which stored in the thyroid follicles . - When T3 and T4 are required ,the protease enzyme acted on - When T3 and T4 are required ,the protease enzyme acted on thyroglobulin to release the free T3 and T4 into the circulation .thyroglobulin to release the free T3 and T4 into the circulation . - The thyroid hormones in the blood are bound to serum protein (thyroid - The thyroid hormones in the blood are bound to serum protein (thyroid binding globulin) and only very small part of it are free in the serum . binding globulin) and only very small part of it are free in the serum . This free fraction of the thyroid hormones is the biological active part .This free fraction of the thyroid hormones is the biological active part . - T3 is more rapid and more potent in its action than T4 .- T3 is more rapid and more potent in its action than T4 .

Hormones of thyroid glands: Hormones of thyroid glands: Hormones secreted by the thyroid :Hormones secreted by the thyroid :

Tetraiodothyronine (T4) or thyroxine.Tetraiodothyronine (T4) or thyroxine. Tri-iodothyronine (T3)Tri-iodothyronine (T3) Thyrocalcitonine, which regulates calcium metabolism . Thyrocalcitonine, which regulates calcium metabolism .

its increase leads to hypocalcemia and vice-versa.its increase leads to hypocalcemia and vice-versa. Hormones acting on the thyroid :Hormones acting on the thyroid :

Thyroid stimulating hormone (T.S.H). it is secreted by the Thyroid stimulating hormone (T.S.H). it is secreted by the anterior pituitary to regulate the thyroid function. Its level rises anterior pituitary to regulate the thyroid function. Its level rises in cases of stress and according to a feed-back mechanism in cases of stress and according to a feed-back mechanism whenever thyroid hormones (T3 and T4) are diminished T.S.H. whenever thyroid hormones (T3 and T4) are diminished T.S.H. increase the vascularity of the gland.increase the vascularity of the gland.

Long Acting Thyroid Stimulator (L.A.T.S). This is an Lg found Long Acting Thyroid Stimulator (L.A.T.S). This is an Lg found in 85% of cases of thyrotoxicosis and may be cause of in 85% of cases of thyrotoxicosis and may be cause of exophthalmos.exophthalmos.

Exophthalmos Producing Substance (E.P.S). This is supposed Exophthalmos Producing Substance (E.P.S). This is supposed to to produce infiltrative changes in the orbit in cases of to to produce infiltrative changes in the orbit in cases of exophthalmos and its level drops after hypophysectomy.exophthalmos and its level drops after hypophysectomy.

CLASSIFICATIONCLASSIFICATION OF OF

GOITREGOITRE

Simple GoiterSimple Goiter It is due to stimulation of thyroid gland by the anterior pituitary It is due to stimulation of thyroid gland by the anterior pituitary

i.e. by increased levels of circulating T.S.H. secretion is increased i.e. by increased levels of circulating T.S.H. secretion is increased by low levels of circulating thyroid hormones. Any factor , by low levels of circulating thyroid hormones. Any factor , therefore that maintains a persistently low level of circulating therefore that maintains a persistently low level of circulating thyroid hormones can be responsible for a simple goitre. The most thyroid hormones can be responsible for a simple goitre. The most important factor is iodine deficiency but , defects in hormone important factor is iodine deficiency but , defects in hormone synthesis may be responsible.synthesis may be responsible.

1. Iodine deficiency :1. Iodine deficiency : one mg/kg/body wt/dailyone mg/kg/body wt/daily - Daily requirement of - Daily requirement of iodine is about iodine is about 100 – 125 mg100 – 125 mg. In endemic areas there is very low . In endemic areas there is very low iodide content in the water and food. The endemic areas are rocky iodide content in the water and food. The endemic areas are rocky mountains , the alps and the Himalayas. In England it is found in mountains , the alps and the Himalayas. In England it is found in Mendips , Chilterns and Cotswolds. Endemic goitres is also found Mendips , Chilterns and Cotswolds. Endemic goitres is also found in low land areas where the water supply comes from far away in low land areas where the water supply comes from far away mountain areas e.g. great lakes of North America , the Nile Valley mountain areas e.g. great lakes of North America , the Nile Valley and the Congo although iodides in food and water may be and the Congo although iodides in food and water may be adequate , failure of intestinal absorption may produce iodine adequate , failure of intestinal absorption may produce iodine deficiency .deficiency .

2.2. Defects in synthesis of thyroid hormones.Defects in synthesis of thyroid hormones. Enzyme deficiency within the thyroid gland.Enzyme deficiency within the thyroid gland. Goitrogens : Goitrogens :

Vegetables of the brassica family (cabbage , kale and Vegetables of the brassica family (cabbage , kale and cauliflower) contains thiocynate.cauliflower) contains thiocynate.

P.A.S / Anti thyroid / cyanides / cyanates sulphur P.A.S / Anti thyroid / cyanides / cyanates sulphur containing drugs.containing drugs.

Iodides in large quantities are goitrogenic as they Iodides in large quantities are goitrogenic as they inhibit the organic binding of iodine and give and inhibit the organic binding of iodine and give and iodide goitre which is usually seen in asthmatics who iodide goitre which is usually seen in asthmatics who have taken proprietary preparations containing iodides have taken proprietary preparations containing iodides over a prolonged period.over a prolonged period.

Genetic enzymatic deficiencies , the condition may Genetic enzymatic deficiencies , the condition may be associated with congenital hypothyroidism.be associated with congenital hypothyroidism.

Natural History of simple GoitreNatural History of simple Goitre: : "stages of goitre formation ""stages of goitre formation "

Persistent T.S.H stimulation causes diffuse hyperplasia all Persistent T.S.H stimulation causes diffuse hyperplasia all lobules are composed of active follicles and iodine uptakes is lobules are composed of active follicles and iodine uptakes is uniform. This is a diffuse hyperplastic goitre which may uniform. This is a diffuse hyperplastic goitre which may persist for along time but , is reversible if T.S.H stimulation persist for along time but , is reversible if T.S.H stimulation stop.stop.

Later , as result of fluctuating T.S.H levels mixed pattern Later , as result of fluctuating T.S.H levels mixed pattern develops with in area of active lobules and areas of inactive develops with in area of active lobules and areas of inactive lobules.lobules.

Active lobules become more vascular and hyperplastic till Active lobules become more vascular and hyperplastic till hemorrhage occurs causing central necrosis and leaving only hemorrhage occurs causing central necrosis and leaving only a surrounding rind of active follicles.a surrounding rind of active follicles.

Necrotic nodules coalesce to form nodules filled either with Necrotic nodules coalesce to form nodules filled either with iodine free colloid or a mass of new but inactive follicles. iodine free colloid or a mass of new but inactive follicles. Continual repetition of this process result in a nodular Continual repetition of this process result in a nodular goitre.goitre.

Clinical types of S.N.G :Clinical types of S.N.G :

1. Diffuse hyperplastic goitre.1. Diffuse hyperplastic goitre.2. Nodular goitre.2. Nodular goitre.3. Solitary nodule.3. Solitary nodule.4. Retrosternal goitre.4. Retrosternal goitre.

1. Diffuse 1. Diffuse hyperplastichyperplastic goitregoitre (physiological and colloid (physiological and colloid goitregoitre))

The diffuse hyperplastic goiter corresponds to the first The diffuse hyperplastic goiter corresponds to the first stages of the natural history of simple goitre.stages of the natural history of simple goitre.

Physiological Physiological goitregoitre : : It occurs usually in female during puberty, menstruation It occurs usually in female during puberty, menstruation

and lactation where the metabolic demands are high. If and lactation where the metabolic demands are high. If T.S.H stimulation stop , the goitre may regress but , tends T.S.H stimulation stop , the goitre may regress but , tends to recur later at times of stress such as pregnancy, the to recur later at times of stress such as pregnancy, the gland is gland is symmetricallysymmetrically enlarged enlarged soft , smooth surface , not soft , smooth surface , not associated with general or local manifestation.associated with general or local manifestation.

Cut sectionCut section the gland is fleshy and pale , the cells lining the gland is fleshy and pale , the cells lining the acini arethe acini are columnar columnar with minimal colloid. with minimal colloid.

Treatment :Treatment : Prophylactic : Iodized table saltProphylactic : Iodized table salt Curative : - Reassurance of the patient and her parentsCurative : - Reassurance of the patient and her parents - L. thyroxin - L. thyroxin

Frequently seen between 15 – 30 years , marked Frequently seen between 15 – 30 years , marked enlargement of gland with smooth surface , soft enlargement of gland with smooth surface , soft consistency , rarely produces local pressure effects consistency , rarely produces local pressure effects by its size. by its size.

Microscopically :Microscopically :the acini are distended with the acini are distended with abundant abundant colloidcolloid and lined with and lined with squamoussquamous cells. cells. Colloid goitre is a late stage of diffuse hyper plastic Colloid goitre is a late stage of diffuse hyper plastic type of goitre when T.S.H stimulation has fallen off type of goitre when T.S.H stimulation has fallen off and when many follicles are inactive and full of and when many follicles are inactive and full of colloid.colloid.

Treatment Treatment :: - Early: L thyroxin - Early: L thyroxin - Late : Subtotal thyroidectomy for huge goiter- Late : Subtotal thyroidectomy for huge goiter

Colloid goitre :

22 . .Nodular GoiterNodular Goiter As regards to natural history of S.N.G , persist As regards to natural history of S.N.G , persist

fluctuating T.S.H stimulation results inevitably in fluctuating T.S.H stimulation results inevitably in progressive nodule formation nodules are usually progressive nodule formation nodules are usually multiple forming a multinodular goitre nodules may multiple forming a multinodular goitre nodules may be colloid or cellular and cystic degeneration and be colloid or cellular and cystic degeneration and hemorrhage are common , as is subsequent hemorrhage are common , as is subsequent calcification when epithelial hyperplasia is marked , calcification when epithelial hyperplasia is marked , it may be associated with hyperthyroidism and it may be associated with hyperthyroidism and condition is then referred to as 2ry toxic goitre. All condition is then referred to as 2ry toxic goitre. All types of S.G are more common in the female than in types of S.G are more common in the female than in male. male.

Clinically :Clinically : the gland is variable in its enlargement not the gland is variable in its enlargement not symmetrical , nodular surface , its consistency may symmetrical , nodular surface , its consistency may be firm , soft or cystic.be firm , soft or cystic.

Diagnosis of S.N.G :Diagnosis of S.N.G : diagnosis of nodular diagnosis of nodular goiture is usually straightforward the pat is goiture is usually straightforward the pat is euthyroid , nodules are palpable and often euthyroid , nodules are palpable and often visible , they are usually visible , they are usually smoothsmooth , , firm firm , , not not hardhard painlesspainless moves with swallowingmoves with swallowing. . Investigation of S.N.G:Investigation of S.N.G:

Thyroid function test to exclude mild hyper Thyroid function test to exclude mild hyper thyroidism.thyroidism.

Estimation of titres of thyroid antibodies to Estimation of titres of thyroid antibodies to differentiate from lymphadenoid goitre.differentiate from lymphadenoid goitre.

Plain X-Ray : may show calcification, Plain X-Ray : may show calcification, tracheal deviation or compression , tracheal deviation or compression , pulmonary metastases, retrosternol goitre.pulmonary metastases, retrosternol goitre.

Complication of nodular goitre :Complication of nodular goitre : 1.1. Toxic changeToxic change : In long standing cases in about 30%. : In long standing cases in about 30%.2.2. HageHage into cystinto cyst : This cause rapid distension of the cyst. : This cause rapid distension of the cyst.3.3. Malig. ChangeMalig. Change : In about 4 – 8 % cases commoner with : In about 4 – 8 % cases commoner with solitary type.solitary type.4. Calcification4. Calcification : Hard nodule. : Hard nodule. 5.5. Pressure effectPressure effect : Dyspnea / dysphagia/ hoarseness of : Dyspnea / dysphagia/ hoarseness of voice.voice.6.6. DisfigurementDisfigurement : when it is big . : when it is big .7.7. TracheomalaciaTracheomalacia : Rare due to long standing goitre : Rare due to long standing goitre

pressing on trachea for long time ending into soft pressing on trachea for long time ending into soft trachea so after operation , collapsing occurs leading trachea so after operation , collapsing occurs leading to suffocation. to suffocation.

Indication for surgical removal of nodular goiter :Indication for surgical removal of nodular goiter : 1. Suspicion of malignancy1. Suspicion of malignancy2. Symptoms of pressure2. Symptoms of pressure3. Hyper thyrodism3. Hyper thyrodism4. Substernal extension4. Substernal extension5. Cosmetic deformity5. Cosmetic deformity6. Solitary nodule that are cold on radio – iodine 6. Solitary nodule that are cold on radio – iodine

scan and solid by ultrasound should be removed.scan and solid by ultrasound should be removed.

Non operative treatment is indicated in Non operative treatment is indicated in Hashimoto’s disease Hashimoto’s disease

Prevention and treatment of simple goitre :Prevention and treatment of simple goitre : All table salt should be iodised. All table salt should be iodised. In endemic areas , the incidence has been reduced by In endemic areas , the incidence has been reduced by

this prophylaxis. this prophylaxis. In early stages a hyper plastic goitre is reversible if 1 In early stages a hyper plastic goitre is reversible if 1

thyroxine is given in maximum doses 0.3 mg daily for thyroxine is given in maximum doses 0.3 mg daily for several months and then very slowly reduction to 0.1 several months and then very slowly reduction to 0.1 mg daily for many years. If regression does not occur .mg daily for many years. If regression does not occur .

Thyroidectomy may be indicated for cosmetic reasons Thyroidectomy may be indicated for cosmetic reasons or pressure symptoms. or pressure symptoms.

Nodular stage of S.G is irreversible so subtotal Nodular stage of S.G is irreversible so subtotal thyroidectomy is indicated. The rule is to leave a thyroidectomy is indicated. The rule is to leave a portion equal to one normal thyroid lobe , on each portion equal to one normal thyroid lobe , on each side.side.

The problem of clinically solitary nodule and The problem of clinically solitary nodule and its evaluation :its evaluation :

Clinically only one macroscopic nodule is Clinically only one macroscopic nodule is found , but microscopic changes will be found , but microscopic changes will be present throughout the gland. This is one form present throughout the gland. This is one form of clinically solitary nodule which is referred of clinically solitary nodule which is referred to as to as cystadenoma of the thyroidcystadenoma of the thyroid and its and its commonest site is at junction of the isthmus commonest site is at junction of the isthmus with one lobe , and although it appears with one lobe , and although it appears solitary multiple small adenomata are solitary multiple small adenomata are scattered around it. When there is a solitary scattered around it. When there is a solitary nodule of thyroid it is must be differentiated nodule of thyroid it is must be differentiated from true adenoma.from true adenoma.

Causes of solitary nodule in thyroid:Causes of solitary nodule in thyroid: 1. solitary nodular goiter. 1. solitary nodular goiter. 2. Toxic nodular goiter. 2. Toxic nodular goiter. 3. Malignant nodule (medullary adenoma) 3. Malignant nodule (medullary adenoma) 4. True adenoma of thyroid. 4. True adenoma of thyroid.

Adenoma of thyroid may be :Adenoma of thyroid may be : Embryonal adenoma Embryonal adenoma Fetal or micro-follicular adenomaFetal or micro-follicular adenoma Colloid or macro-follicular adenoma Colloid or macro-follicular adenoma Hurthle-cell adenoma with acidophilic cytoplasm Hurthle-cell adenoma with acidophilic cytoplasm Papillary cystadenoma highly suspicious of being malignant.Papillary cystadenoma highly suspicious of being malignant.

Diagnoses of solitary nodule in thyroidDiagnoses of solitary nodule in thyroid1. Clinically1. Clinically Many cases are asymptomaticMany cases are asymptomatic The solitary nodule in thyroid is more likely be malignant than The solitary nodule in thyroid is more likely be malignant than

multi nodular goitre.multi nodular goitre. A thyroid nodule is more likely to be cancer in man than in A thyroid nodule is more likely to be cancer in man than in

woman.woman. Patient with thyroid nodules who received X-Ray treatment to the Patient with thyroid nodules who received X-Ray treatment to the

head and neck in infancy and childhood have 35 – 50 % chance of head and neck in infancy and childhood have 35 – 50 % chance of having thyroid cancer.having thyroid cancer.

cystic lesions less than 10 Cm in diameter are almost never cancer.cystic lesions less than 10 Cm in diameter are almost never cancer. Toxic manifestation in toxic nodule Toxic manifestation in toxic nodule Malignant features in malignant nodule Malignant features in malignant nodule

2. Investigations2. Investigations A.A. is helpful in determining whether the lesion is single or is helpful in determining whether the lesion is single or

multiple and whether it is functioning (hot) or non functioning (cold).multiple and whether it is functioning (hot) or non functioning (cold). Hot noduleHot nodule = overactive nodule = overactive nodule Takes up isotope , while the surrounding tissue does not , here , the Takes up isotope , while the surrounding tissue does not , here , the

surrounding. T. is inactive because the nodule is producing such high surrounding. T. is inactive because the nodule is producing such high levels of thyroid hormones that T.S.H is suppressed.levels of thyroid hormones that T.S.H is suppressed.

Worm noduleWorm nodule = active nodule = active nodule Takes up isotope and so does normal surrounding tissue about it.Takes up isotope and so does normal surrounding tissue about it. Cold noduleCold nodule = inactive nodule Takes up no isotope = inactive nodule Takes up no isotope D.D of cold nodule : degenerative cyst, calcification, haemorrhage,D.D of cold nodule : degenerative cyst, calcification, haemorrhage,

abscess or hydatid cyst.abscess or hydatid cyst.N.B.N.B. The fluorescent scanning using a collimated source of radiation is The fluorescent scanning using a collimated source of radiation is

now used to differentiate benign from malignant thyroid nodules. now used to differentiate benign from malignant thyroid nodules. This procedure has advantage that no radio – active materials are This procedure has advantage that no radio – active materials are introduced into the body.introduced into the body.

Thyroid scan :

B. Ultrasound (echography)B. Ultrasound (echography) • It is helpful to differentiate solitary from multiple nodulesIt is helpful to differentiate solitary from multiple nodules• It is also used for differentiating solid from cystic It is also used for differentiating solid from cystic

lesions .lesions .C. Biopsy C. Biopsy • FNAC or Trucut or Excisional biopsy.FNAC or Trucut or Excisional biopsy.

N.B.N.B. Percutaneous needle biopsy is helpful if good endocrine Percutaneous needle biopsy is helpful if good endocrine

cytologists are available , needle biopsy should not cytologists are available , needle biopsy should not performed in patients with history of irradiation to the performed in patients with history of irradiation to the neck, because radiation – induced tumors are often neck, because radiation – induced tumors are often multi focal and –ve biopsy may therefore be unreliable.multi focal and –ve biopsy may therefore be unreliable.

3. Treatment : 3. Treatment : A.A. Enucleation :Enucleation : Removal of the nodule from its capsule. Removal of the nodule from its capsule. But it is not recommended because recurrenceBut it is not recommended because recurrence is the rule as the nodule is never solitary.is the rule as the nodule is never solitary.B. Resection Enucleation :B. Resection Enucleation : Excision of the nodule with the Excision of the nodule with the surrounding thyroid tissue.surrounding thyroid tissue. It is the recommended operation asIt is the recommended operation as we remove the scattered small nodules we remove the scattered small nodules around the clinical solitary nodule.around the clinical solitary nodule.C. Hemithyroidectomy :C. Hemithyroidectomy : Removal of the affected lobe together Removal of the affected lobe together with the isthmus and pyramidal lobe.with the isthmus and pyramidal lobe. The specimen must be sent for biopsy.The specimen must be sent for biopsy. It is the operation of choice.It is the operation of choice.

N.B. N.B. The term thyrotoxicosis is retained because hyperthyroidism i.e. The term thyrotoxicosis is retained because hyperthyroidism i.e.

symptoms due to a raised level of circulating thyroid hormonessymptoms due to a raised level of circulating thyroid hormones are not responsible for all manifestations of the disease.are not responsible for all manifestations of the disease.

Toxic Goitre Toxic Goitre Clinical Types :Clinical Types : 1. primary toxic goitre (Grave’s disease)1. primary toxic goitre (Grave’s disease) 2. Toxic nodular goitre (2ry toxic) 2. Toxic nodular goitre (2ry toxic) 3. Toxic nodule 3. Toxic nodule 4. Hyper thyrodism due to rare cases.4. Hyper thyrodism due to rare cases.

1.1. Primary Toxic Primary Toxic GoitreGoitre : (Greave’s disease) : (Greave’s disease) It is a diffuse vascular goitre appearing at the same time as the hyperIt is a diffuse vascular goitre appearing at the same time as the hyper thyroidism usually in the younger woman than man (8 times), and thyroidism usually in the younger woman than man (8 times), and

frequently associated with eye signs. frequently associated with eye signs. The onset is usually insidious with insomnia , irritability and wt loss. The onset is usually insidious with insomnia , irritability and wt loss.

Sometimes the onset is acute and the course may be progressive or Sometimes the onset is acute and the course may be progressive or intermittent.intermittent.

The whole of the functioning thyroid tissue isThe whole of the functioning thyroid tissue is involved and the hypertrophy and hyperplasia are due to abnormal involved and the hypertrophy and hyperplasia are due to abnormal

thyroid stimulators such as L.A.T.S which is an immunoglobulin , thyroid stimulators such as L.A.T.S which is an immunoglobulin , found in 85% of cases of thyrotoxicosis.found in 85% of cases of thyrotoxicosis.

Grave`s disease is considered now an auto immune disease in whichGrave`s disease is considered now an auto immune disease in which antibodies binding to T.S.H receptors leading to release of thyroxine. antibodies binding to T.S.H receptors leading to release of thyroxine.

I. Pathology :I. Pathology : A. Gross appearance :A. Gross appearance : The gland : is moderately enlarged , brick red in The gland : is moderately enlarged , brick red in

colour and highly vascular, fleshy in consistency colour and highly vascular, fleshy in consistency with an opaque meaty appearance. In some cases no with an opaque meaty appearance. In some cases no enlargement is detected clinically and even at enlargement is detected clinically and even at operation the gland may not enlarged at all. The operation the gland may not enlarged at all. The enlargement is characteristically diffuse although enlargement is characteristically diffuse although one lobe may be more affected than the other.one lobe may be more affected than the other.

B. Microscopically :B. Microscopically : Marked hyperplasia of the cells , which become Marked hyperplasia of the cells , which become

arranged in several layers.arranged in several layers. Marked diminution of the lumen of the acini.Marked diminution of the lumen of the acini. Disappearance of the colloid from the lumenDisappearance of the colloid from the lumen.. Marked lymphocytic infiltration Marked lymphocytic infiltration

II. II. Clinical FeaturesClinical Features :: Thyrotoxicosis affects all the systems of the body startingThyrotoxicosis affects all the systems of the body starting with excitation and ending with failure or depressionwith excitation and ending with failure or depression Wayne’s clinical diagnostic index gives all the important Wayne’s clinical diagnostic index gives all the important

symptoms and signs of thyrotoxicosis and indicates by their scoresymptoms and signs of thyrotoxicosis and indicates by their score the relative importance of each.the relative importance of each.Cardinal signs of thyrotoxicasis are : E + 3TCardinal signs of thyrotoxicasis are : E + 3T 1. Eye manifestation.1. Eye manifestation. 2. Tremors2. Tremors 3. Tachycardia.3. Tachycardia. 4. Tumors 4. Tumors Cardinal symptoms of thyrotoxicasis are : HLPCardinal symptoms of thyrotoxicasis are : HLP 1. Heat intolerance.1. Heat intolerance. 2. Loss of weight in-spite of good appetite.2. Loss of weight in-spite of good appetite. 3. Palpitation.3. Palpitation.

A) General FeaturesA) General Features 1. C.V.S1. C.V.Sa)a) Dyspnea on exertion , palpitation , tachycardia are early featuresDyspnea on exertion , palpitation , tachycardia are early featuresb)b) Slight elevation of systolic pressure. with decrease of Slight elevation of systolic pressure. with decrease of

diastolic pressure so that , the pulse pressure is increased. The diastolic pressure so that , the pulse pressure is increased. The pulse is easily felt at the wrist (water hammer pulse).pulse is easily felt at the wrist (water hammer pulse).

c)c) Auricular fibrillation and heart failure may occur but , this is Auricular fibrillation and heart failure may occur but , this is more usual in 2ry toxic goitre.more usual in 2ry toxic goitre.

2. C.N.S 2. C.N.S a)a) Insomnia, occurs early in the course of the disease.Insomnia, occurs early in the course of the disease.b)b) Irritability , anxiety and tremors of out stetted hands and Irritability , anxiety and tremors of out stetted hands and

protruding tongue are common features.protruding tongue are common features.c)c) In severe cases , mania may be present.In severe cases , mania may be present.3. Metabolic disturbances : 3. Metabolic disturbances : a)a) Loss of weight in-spite of good appetite.Loss of weight in-spite of good appetite.b)b) Sweating especially of the palms of hands , which feel worm.Sweating especially of the palms of hands , which feel worm.c)c) Intolerance to heat the patient can tolerate cold weather well.Intolerance to heat the patient can tolerate cold weather well.d)d) Flushing and feeling of hotness.Flushing and feeling of hotness.

4. Gastro – intestinal :4. Gastro – intestinal : Polyphagia i.e. increased appetite, later there may be loss of appetite.Polyphagia i.e. increased appetite, later there may be loss of appetite. Abdominal pains.Abdominal pains. Looseness of stools or even diarrhea.Looseness of stools or even diarrhea.5. Sexual system.5. Sexual system.a)a) Menorrhagia, dysmenorrhea or amenorrhea.Menorrhagia, dysmenorrhea or amenorrhea.b)b) In male , at first there is increase sexual desire, later the patient may In male , at first there is increase sexual desire, later the patient may

become impotent.become impotent.6. Muscle – skeletal system6. Muscle – skeletal system a)a) Bone pains due to osteoporosis Bone pains due to osteoporosis b)b) Muscle weakness (thyrotoxic myopathy or myasthenia)Muscle weakness (thyrotoxic myopathy or myasthenia)7. Urinary system7. Urinary system a)a) Polyuria Polyuria b)b) Glycosuria Glycosuria 8. Skin 8. Skin a)a) Flushing Flushing b)b) Abdominal pigmentation Abdominal pigmentation

c)c) PretibialPretibial myxedemamyxedema It is thickening of skin by a mucin – like deposit. It is It is thickening of skin by a mucin – like deposit. It is

rare sign of thyrotoxicosis but may occur at any stage of rare sign of thyrotoxicosis but may occur at any stage of the disease it is usually follows thyroidectomy , Iodin the disease it is usually follows thyroidectomy , Iodin therapy or prolonged antithyroid ttherapy or prolonged antithyroid treatment .reatment .

It is usually associated with progressive exophthalmos.It is usually associated with progressive exophthalmos. It starts as bilateral symmetrical pitting edema with red and It starts as bilateral symmetrical pitting edema with red and

then deep purple colour. then deep purple colour. In severe cases , whole leg below its knee is involved In severe cases , whole leg below its knee is involved

“thyroid acropachy”. Although it is resistant to treatment . “thyroid acropachy”. Although it is resistant to treatment . it tends to subside spontaneously.it tends to subside spontaneously.

B) Thyroid manifestationB) Thyroid manifestation Moderately, symmetrical enlargement of thyroid gland Moderately, symmetrical enlargement of thyroid gland with smooth surface and firm or rubbery in consistency with smooth surface and firm or rubbery in consistency associated with increased vascularity.associated with increased vascularity.Evidence of increased vascularity :Evidence of increased vascularity :1.1. Dilated vein on the skinDilated vein on the skin2.2. Hot sensation Hot sensation 3.3. Bruit may be felt Bruit may be felt 4.4. Murmur may be heard.Murmur may be heard. Sometimes the enlargement is very small or no Sometimes the enlargement is very small or no

enlargement at all, this type occurs in old patients enlargement at all, this type occurs in old patients who present with weight loss and myasthenia over who present with weight loss and myasthenia over a long period, the eye manifestation in that cases is a long period, the eye manifestation in that cases is absent and the heart is mainly affected so it may absent and the heart is mainly affected so it may be pass into heart failure while the original causes be pass into heart failure while the original causes are over locked .are over locked .

C) Eye ManifestationC) Eye Manifestation Exopthalmos is commonly classified into 4 grades :Exopthalmos is commonly classified into 4 grades :1.1. Mild :Mild : consists of widening of the palpepral fissure due to consists of widening of the palpepral fissure due to retraction of the upper eyelids without any bulging ofretraction of the upper eyelids without any bulging of the eyes. the eyes.

SteStellllwag’s sign and Von Graefe’s sign are positive.wag’s sign and Von Graefe’s sign are positive.2.2. Moderate :Moderate : due to actual bulging of eyeballs from increased due to actual bulging of eyeballs from increased compositions of retrobulbar fat.compositions of retrobulbar fat.

Darlymple and Joffroy’s signs are positive.Darlymple and Joffroy’s signs are positive.3.3. Severe :Severe : due to intra – orbital oedema and congestion , due to intra – orbital oedema and congestion ,

marked protrusion of the eye balls is associated with watering marked protrusion of the eye balls is associated with watering of the eyes , dilatation of conjunctival vessels and muscle of the eyes , dilatation of conjunctival vessels and muscle paresis.paresis.

Limitation of movement in an upwards and outwards Limitation of movement in an upwards and outwards directions, also downwards and inwards directions must be directions, also downwards and inwards directions must be tested.tested.

Moebius signs is positiveMoebius signs is positive

4.4. Malignant exophthalmos :Malignant exophthalmos : It is a progressive form , which may increased after It is a progressive form , which may increased after

otherwise successful treatment of thyrotoxicosis otherwise successful treatment of thyrotoxicosis particularly by thyrodectomy increasing exophthalmos is particularly by thyrodectomy increasing exophthalmos is associated with chemosis of conjunctiva impairment of associated with chemosis of conjunctiva impairment of corneal sensibility and paralysis of the eye muscles with corneal sensibility and paralysis of the eye muscles with grave risks of corneal ulceration, panophthalmitis and loss grave risks of corneal ulceration, panophthalmitis and loss of vision. of vision.

Exophthalmos of graves disease is probably due to Exophthalmos of graves disease is probably due to infiltration of retrobulbar tissues with fluid and round infiltration of retrobulbar tissues with fluid and round cells with varying degree of retraction or spasm of upper cells with varying degree of retraction or spasm of upper eyelid the cause is unknown but it is not due to an increase eyelid the cause is unknown but it is not due to an increase of T.S.H as it is not found in mxyedema where TSH is at of T.S.H as it is not found in mxyedema where TSH is at its highest level.its highest level.

L.A.T.S or E.P.S may be responsible. L.A.T.S or E.P.S may be responsible. The condition is usually bilateral but unilateral mayThe condition is usually bilateral but unilateral may occur in rare cases.occur in rare cases.

Stellwag’s sign :Stellwag’s sign : infrequency of blinking with a infrequency of blinking with a staring look.staring look.

Von graefe’s sign :Von graefe’s sign : upper lid lays behind the eye upper lid lays behind the eye ball as the patient looks down without moving the ball as the patient looks down without moving the head.head.

Dalrymple‘s sign :Dalrymple‘s sign : a rim of white sclera between a rim of white sclera between the upper eye lid and upper edge of cornea due to the upper eye lid and upper edge of cornea due to retraction of upper lid and protrusion of the eye retraction of upper lid and protrusion of the eye ball.ball.

Joffroy’s sign :Joffroy’s sign : lack of wrinkling of the forehead lack of wrinkling of the forehead on looking upwards without moving the head.on looking upwards without moving the head.

Moebius sign :Moebius sign : imperfect convergence on looking imperfect convergence on looking at a near object due to muscular paresis (medial at a near object due to muscular paresis (medial recti muscles)recti muscles)

N.B.N.B. Other causes of exophthalmos : Other causes of exophthalmos : 1. A space – occupying lesion in orbit.1. A space – occupying lesion in orbit.2. Cavernous sinus thrombosis.2. Cavernous sinus thrombosis.

Treatment of exophthalmos :Treatment of exophthalmos :I. I. Mild cases Mild cases ( most common ) : ( most common ) : It is usually self limiting and may even regress It is usually self limiting and may even regress treatment of thyrotoxicosis will improve the eye signs.treatment of thyrotoxicosis will improve the eye signs. lid retraction disappears in 2/3 of cases.lid retraction disappears in 2/3 of cases.II. Severe cases II. Severe cases ( rare ):( rare ): The proptosis can be measured with an exophthalmometer.The proptosis can be measured with an exophthalmometer.1.1. Protection of eye (wind – dust – sun)Protection of eye (wind – dust – sun)2.2. Sleep sitting to decrease venous pressure.Sleep sitting to decrease venous pressure.3.3. Lateral tarsorrhaphy may be needed.Lateral tarsorrhaphy may be needed.4.4. Prednisone with massive doses + metronidazole (flagyl)Prednisone with massive doses + metronidazole (flagyl)5.5. Irradiation of retro orbital Tissue may be necessary.Irradiation of retro orbital Tissue may be necessary.• Pituitary : Pituitary : irradiationirradiation stalk sectionstalk section cryo surgerycryo surgery• Orbital decompression (trans-frontal and trans-antral) Orbital decompression (trans-frontal and trans-antral)

2. Secondary toxic goiter2. Secondary toxic goiter

Here a simple nodular goitre is present for long time before the hyperthyroidism. Here a simple nodular goitre is present for long time before the hyperthyroidism. In many cases of toxic nodular goitre ,the nodules are inactive and it is the In many cases of toxic nodular goitre ,the nodules are inactive and it is the

internodular thyroid tissue that is over active , here the hyperthyroidism is due to internodular thyroid tissue that is over active , here the hyperthyroidism is due to abnormal thyroid stimulators such as L.A.T.S. abnormal thyroid stimulators such as L.A.T.S.

In some toxic nodular goitre one or more nodules are overactive and here the In some toxic nodular goitre one or more nodules are overactive and here the hyperthyroidism is due to autonomous thyroid tissue as in toxic nodule. hyperthyroidism is due to autonomous thyroid tissue as in toxic nodule. The 2ry toxic goitre differs from Grave’s diseases in the following : The 2ry toxic goitre differs from Grave’s diseases in the following : The thyroid gland is nodular either prior to toxic manifestation or nodularity and The thyroid gland is nodular either prior to toxic manifestation or nodularity and

toxicity started together.toxicity started together. C.V. manifestations are prominent and nervous manifestation are less marked than C.V. manifestations are prominent and nervous manifestation are less marked than

in Grave’s disease.in Grave’s disease. Proptosis is usually absent.Proptosis is usually absent. Medical treatment is less effective and has to be given for long periods to obtain a Medical treatment is less effective and has to be given for long periods to obtain a

response.response. Recurrence of symptoms after thyroidectomy : for 2ry toxic goitre is rare (1% or Recurrence of symptoms after thyroidectomy : for 2ry toxic goitre is rare (1% or

less) where as in grave’s disease the incidence of recurrence is from 10 to 20 less) where as in grave’s disease the incidence of recurrence is from 10 to 20 percent.percent.

Post operative myxedema is extremely rare in 2ry toxic goitre but it is frequent in Post operative myxedema is extremely rare in 2ry toxic goitre but it is frequent in graves’s disease.graves’s disease.

2ry toxic goitre occurs in an older age group it is better treated surgically because 2ry toxic goitre occurs in an older age group it is better treated surgically because the other lines of treatment usually fail to control it.the other lines of treatment usually fail to control it.

More ever the cardiac affection which is commonly associated with it responds to More ever the cardiac affection which is commonly associated with it responds to surgical removal of the goitre.surgical removal of the goitre.

3. Toxic Nodule3. Toxic NoduleIt is solitary over active nodule (hot nodule)It is solitary over active nodule (hot nodule)

4. Thyrotoxicosis due to other causes4. Thyrotoxicosis due to other causes1.1. Thyrotoxicosis fastitiaThyrotoxicosis fastitia Patients whose given thyroxine as tonic.Patients whose given thyroxine as tonic.2. Jod-basedow thyrotoxicosis2. Jod-basedow thyrotoxicosis when large doses of iodide were given for an endemic when large doses of iodide were given for an endemic

goitre.goitre.3.3. Neonatal thyrotoxicosisNeonatal thyrotoxicosis It occurs in babies who were born from hyperthyroid It occurs in babies who were born from hyperthyroid

mothers. mothers. L.A.T.S titres in both mother and child will be high.L.A.T.S titres in both mother and child will be high. Hyperthyroidism manifestation will be gradually Hyperthyroidism manifestation will be gradually

subsides in subsides in 3 or 4 weeks3 or 4 weeks

Investigations for Investigations for thyrotoxicosisthyrotoxicosis

1. Clinical diagnosis by Wayne 1. Clinical diagnosis by Wayne Diagnostic Index.Diagnostic Index.

2. Sleeping pulse.2. Sleeping pulse.3. Thyroid function tests3. Thyroid function tests Sleeping pulseSleeping pulseIt is very important in grading the It is very important in grading the

severity of thyrotoxicosis severity of thyrotoxicosis 80 – 90 Mild case80 – 90 Mild case90 – 110 Moderate case90 – 110 Moderate caseAbove 110 Severe caseAbove 110 Severe case

Thyroid function testsThyroid function tests1. Measurements of thyroid hormone in serum1. Measurements of thyroid hormone in serumA. Serum protein bound iodine ( P.B.I. ) A. Serum protein bound iodine ( P.B.I. ) B. Total serum thyroxine ( T4 )B. Total serum thyroxine ( T4 )C. Total serum T3C. Total serum T3D. Free serum T4D. Free serum T4E. Thyroid indexE. Thyroid index 2. Measurements of free binding sites for 2. Measurements of free binding sites for

thyroid hormonesthyroid hormones3. Uptake and discharge of radio active iodine3. Uptake and discharge of radio active iodineA. Radio active iodine uptake.A. Radio active iodine uptake.B. T3 resin uptake test .B. T3 resin uptake test .C. T3 suppression test “ werner “.C. T3 suppression test “ werner “.D. Thyroid scanning.D. Thyroid scanning.E. Iodine clearance test. E. Iodine clearance test.

4. Miscellaneous tests4. Miscellaneous tests A.A. B.M.R N. -10% to +15% of the standardB.M.R N. -10% to +15% of the standard ( 40 cal. / square meter / surface area / ( 40 cal. / square meter / surface area /

hour )hour ) False results in : neurosis / False results in : neurosis /

pregnancy / fever.pregnancy / fever.B. Serum cholesterol : normal 150 – 250 mg%B. Serum cholesterol : normal 150 – 250 mg% It is decreased in thyrotoxicosis & It is decreased in thyrotoxicosis &

Increased in myxedema.Increased in myxedema. False result in : hypercholesteremia.False result in : hypercholesteremia.C. Serum creatinine : normal 0.6 mg/100 mlC. Serum creatinine : normal 0.6 mg/100 ml It increased in thyrotoxicosisIt increased in thyrotoxicosis False increase in renal failure.False increase in renal failure.D. E.C.G. D. E.C.G.

Protein bound iodine P.B.IProtein bound iodine P.B.I iodine containing hormones T3 and T4 are iodine containing hormones T3 and T4 are

transported in the plasma mainly by specific transported in the plasma mainly by specific binding proteins (thyroxine binding globulin) binding proteins (thyroxine binding globulin) (T.B.G). As only a very small amount of T3 and (T.B.G). As only a very small amount of T3 and T4 are free in the blood, The P.B.I effectively T4 are free in the blood, The P.B.I effectively represents total circulation Thyroid hormones. represents total circulation Thyroid hormones.

The euthyroid rang The euthyroid rang 4 – 8 Mg/100ml4 – 8 Mg/100ml False low results in :False low results in : hereditary decrease of T.B.Ghereditary decrease of T.B.G Nephrotic syndrome.Nephrotic syndrome. False high results in:False high results in: X-ray contrast media containing Iodine X-ray contrast media containing Iodine

biligrafin biligrafin Expectorants containing Iodine, Lugol’s Iodine Expectorants containing Iodine, Lugol’s Iodine Pregnancy Pregnancy Oral contraceptives Oral contraceptives Estrogen administration Estrogen administration Early hepatitis Early hepatitis

Total serum T3 - free Serum T4Total serum T3 - free Serum T4 Both measured by Radio - Immuno Both measured by Radio - Immuno

assay, and are available in special assay, and are available in special laboratories, but, they will eventually laboratories, but, they will eventually become routine tests, for the become routine tests, for the twotwo reasons reasons

1- Some cases of hyper thyroidism are due 1- Some cases of hyper thyroidism are due to excessive production of T3 without to excessive production of T3 without any accompanying rise in level of serum any accompanying rise in level of serum P.B.I or total serum T4 P.B.I or total serum T4

2- Free serum T4 ( which not protein 2- Free serum T4 ( which not protein bound) is far more representative of the bound) is far more representative of the level of hormone available to the level of hormone available to the individual thyroid cell than is the total individual thyroid cell than is the total serum T4.serum T4.

2- Measurement of free binding sites for thyroid hormones 2- Measurement of free binding sites for thyroid hormones in the blood : in the blood :

Radio active T3 is incubated with patient’s serum so that it Radio active T3 is incubated with patient’s serum so that it becomes fixed to any thyroid binding protein not already becomes fixed to any thyroid binding protein not already carrying T3 or T4.carrying T3 or T4.

The amount so fixed can be measured and from this can be The amount so fixed can be measured and from this can be estimated the number of binding sites in the serum which are estimated the number of binding sites in the serum which are un occupied.un occupied.

In the hyperthyroidism, the number of free binding sites is In the hyperthyroidism, the number of free binding sites is low because a few are not already carrying hormone low because a few are not already carrying hormone

In hypothyroidism and myxedema, the number of free sites In hypothyroidism and myxedema, the number of free sites are high.are high.

This is not accurate test in itself , but in conjunction with the This is not accurate test in itself , but in conjunction with the total serum T4 or serum P.B.I total serum T4 or serum P.B.I

the free thyroxinthe free thyroxin indexindex can be calculated from the formula: can be calculated from the formula: FTI FTI = serum T4 or (B.P.I) × T3 uptake percent = serum T4 or (B.P.I) × T3 uptake percent euthyroid range of FTI 2.5 – 7.0euthyroid range of FTI 2.5 – 7.0

3. Uptake and discharge of radio active 3. Uptake and discharge of radio active iodine :iodine :

A. Radio active iodine uptake.A. Radio active iodine uptake. normal thyroid uptake is normal thyroid uptake is 15 – 55 %15 – 55 % of the of the

given dose in thyrotoxicosis the uptake given dose in thyrotoxicosis the uptake increase above 55% in hypothyrodism it increase above 55% in hypothyrodism it decrease below decrease below 10%10% technique.technique.

1- No drugs or materials containing iodine are 1- No drugs or materials containing iodine are allowed for the previous 3 weeks.allowed for the previous 3 weeks.

2- 2- 5 Micro curies5 Micro curies of radio active iodine are given of radio active iodine are given by mouth in a small amount of water or milk it by mouth in a small amount of water or milk it is rapidly absorbed from the small bowel into is rapidly absorbed from the small bowel into blood and the thyroid and kidneys compete for blood and the thyroid and kidneys compete for it in hyper thyroidism the thyroid uptake is it in hyper thyroidism the thyroid uptake is rapid and little is excreted in the urine.rapid and little is excreted in the urine.

3- 3- After 24h the uptake is measured over the thyroid by Geiger After 24h the uptake is measured over the thyroid by Geiger Muller Counter. Muller Counter.

B- T3 Resin uptake test :B- T3 Resin uptake test : By incubating iodine T3 (Radioactive By incubating iodine T3 (Radioactive

T3) with patient’s serum. Part of T3 T3) with patient’s serum. Part of T3 is fixed by plasma protein and the is fixed by plasma protein and the part which is not fixed is part which is not fixed is precipitated precipitated by resinby resin and estimated. and estimated. In the hyperthyroidism , the proteins In the hyperthyroidism , the proteins are already saturated with thyroxine are already saturated with thyroxine and the resin uptake is highand the resin uptake is high

in the hypothyroidism the resin in the hypothyroidism the resin uptake is low. This is another vitro uptake is low. This is another vitro test through which hazards of test through which hazards of irradiation are thus avoided.irradiation are thus avoided.

C- T3 suppression test “Werner”.C- T3 suppression test “Werner”. Goitre due to iodine deficiency in endemic areas Goitre due to iodine deficiency in endemic areas

has a rapid radio active iodine uptake , but has a rapid radio active iodine uptake , but simple goitre is under T.S.H control so that simple goitre is under T.S.H control so that uptake can be diminished by suppressing T.S.H uptake can be diminished by suppressing T.S.H that is done by giving 40 Mg every 8 hourly for that is done by giving 40 Mg every 8 hourly for 7 days.7 days.

In a toxic goitre In a toxic goitre 10 – 20 %10 – 20 % reduction in uptake reduction in uptake by suppression whole in simple goitre by suppression whole in simple goitre 50 – 80%50 – 80% reduction. reduction.

D- Thyroid scanningD- Thyroid scanning scanning of thyroid after a tracer dose of scanning of thyroid after a tracer dose of

radio active iodine shows which parts of radio active iodine shows which parts of the gland are functioning or functionless the gland are functioning or functionless (Hot or Cold) : whilst scanning is (Hot or Cold) : whilst scanning is sometimes helpful in cases of thyroid sometimes helpful in cases of thyroid carcinoma its principle value is in the carcinoma its principle value is in the diagnosis of toxic nodule either as solitary diagnosis of toxic nodule either as solitary or as a part of toxic multinodular goitre.or as a part of toxic multinodular goitre.

E- Iondine clearance test :E- Iondine clearance test : in thyrotoxicosis most of isotope is taken in thyrotoxicosis most of isotope is taken

by thyroid and there fore there is less by thyroid and there fore there is less excretion of radio active iodine by the excretion of radio active iodine by the kidney. The normal range of excretion in kidney. The normal range of excretion in 48h is 48h is 30 – 70%30 – 70% of given dose of given dose lower valueslower values are suggestive of thyrotoxicosis. are suggestive of thyrotoxicosis.

D.D of thyrotoxicosisD.D of thyrotoxicosis Anxiety.Anxiety. Neurosis.Neurosis. HT disease.HT disease. Myasthenia.Myasthenia. T.B.T.B. Pheochromocytoma.Pheochromocytoma. Menopausal syndromeMenopausal syndrome Other causes of exophthalmos.Other causes of exophthalmos.

How do you differentiate between psychoneurosis and How do you differentiate between psychoneurosis and thyrotoxicosis ?thyrotoxicosis ? Anorexia is an invariable presentation in Anorexia is an invariable presentation in

psychoneurosis while polyphagia is always present psychoneurosis while polyphagia is always present in thyrotoxicosis taking notice , in thyrotoxicosis taking notice ,

in both , there is loss of weight.in both , there is loss of weight. Sleeping pulse normal in psychoneurosis.Sleeping pulse normal in psychoneurosis. Although the hands show tremors and sweating in Although the hands show tremors and sweating in

both conditions , but the hand is hot in both conditions , but the hand is hot in thyrotoxicosis and cold in psychoneurosis.thyrotoxicosis and cold in psychoneurosis.

Thyroid function tests are normal in Thyroid function tests are normal in psychoneurosis.psychoneurosis.

Treatment of Toxic Treatment of Toxic GoitreGoitre

1. Medical treatment1. Medical treatment Indications :Indications :

Mild cases.Mild cases. Thyrotoxicosis occuring during Thyrotoxicosis occuring during

periods of stress. As puberty , periods of stress. As puberty , pregnancy and lactation. Anti thyroid pregnancy and lactation. Anti thyroid drugs are given in accurate does and drugs are given in accurate does and it is better to be on under dose side. it is better to be on under dose side. They are stopped one month before They are stopped one month before delivery and lugol’s iodine given delivery and lugol’s iodine given instead.instead.

Recurrent cases after operation Recurrent cases after operation specially 2nd recurrence for fear of specially 2nd recurrence for fear of injuring the recurrent laryngeal injuring the recurrent laryngeal nerves. (Patient under 45y).nerves. (Patient under 45y).

Bad general conditions as HT failure.Bad general conditions as HT failure. Progressive exophthalmos.Progressive exophthalmos.

Aim of treatment :Aim of treatment : Inhibit the function of the gland without Inhibit the function of the gland without

destroyingdestroying it.it.Advantages :Advantages :

No surgery.No surgery. No use of radio active materials.No use of radio active materials.

Disadvantages :Disadvantages : The treatment is The treatment is prolongedprolonged and the and the

failure rate after course of 1.5 or 2 failure rate after course of 1.5 or 2 years is at least 50 % years is at least 50 %

It is It is impossible to predictimpossible to predict which which patient is likely to go into a remission.patient is likely to go into a remission.

Some goitres enlarge and become Some goitres enlarge and become very very vascularvascular during treatment leading to during treatment leading to pressure symptomspressure symptoms and making the and making the surgery is difficult .surgery is difficult .

Very rarely , there is a dangerous drug Very rarely , there is a dangerous drug reaction e.g. reaction e.g. a granulocytosisa granulocytosis (0.1 – (0.1 – 0,4%). The drug is stopped if sore throat 0,4%). The drug is stopped if sore throat develops or white count drops and the develops or white count drops and the patient is given penicillin and patient is given penicillin and streptomycin as a guard against streptomycin as a guard against infection.infection.

AllergicAllergic manifestation as itching – manifestation as itching – vomiting and rashes.vomiting and rashes.

Persistent tachycardiaPersistent tachycardia due to marked due to marked vascularity this may mislead the vascularity this may mislead the physician to increase the dose of anti physician to increase the dose of anti thyroids to degree of producing thyroids to degree of producing myxoedema. Thickening of vocal cords myxoedema. Thickening of vocal cords and aedema of the glottis may occur and and aedema of the glottis may occur and may necessitate tracheostomy.may necessitate tracheostomy.

Myxoedema.Myxoedema.

Drugs used :Drugs used :

Thiouracil.Thiouracil.Methyl thiouracil 300 – 600 Methyl thiouracil 300 – 600 mg /day.mg /day.

Propyl thiouracil 200 – 300 Propyl thiouracil 200 – 300 mg/daymg/day

Neomercazol 5 – 15 mg/T.D.SNeomercazol 5 – 15 mg/T.D.SPotassium Perchlorate 200 – Potassium Perchlorate 200 – 800 mg/day800 mg/day

Scheme of treatment :Scheme of treatment : The patient is given for The patient is given for one monthone month if there is if there is

improvement it is continued for up improvement it is continued for up 3 months3 months then the dose is then the dose is halved for another 3 monthshalved for another 3 months. . After 6 months one fourth of the original doseAfter 6 months one fourth of the original dose is given for another is given for another one yearone year on the whole the on the whole the course takes about course takes about 1.5 year1.5 year..

It is most important to maintain high It is most important to maintain high concentration of the drug through out 24 h by concentration of the drug through out 24 h by spacing the doses at three times daily.spacing the doses at three times daily.

IfIf there is no improvement after the there is no improvement after the first first monthmonth , it is better to shift to surgical , it is better to shift to surgical treatment because further medical treatment treatment because further medical treatment will be ineffective and will increase the will be ineffective and will increase the vascularity of the gland markedly so that the vascularity of the gland markedly so that the operation will be very difficult.operation will be very difficult.

The results of medical treatment :The results of medical treatment : 50%50% of cases are cured completely. of cases are cured completely.50%50% of cases will go into relapse , these of cases will go into relapse , these

are treated either by surgery or radio are treated either by surgery or radio active iodine.active iodine.

With anti-thyroid drugs, the following is With anti-thyroid drugs, the following is essential :essential :

1. Rest physically and mentally 1. Rest physically and mentally 2. Sedation by luminal 2. Sedation by luminal 3. Diet and fluids 3000 cal/daily3. Diet and fluids 3000 cal/daily4. Inderal.4. Inderal.This measures make your mild cases This measures make your mild cases

without any anti-thyroid drugswithout any anti-thyroid drugs

22 . .Radio active iodineRadio active iodine Indications :Indications : recurrent cases after recurrent cases after

surgery (over 45y) bad risky cases due surgery (over 45y) bad risky cases due to age or disease.to age or disease.

Aim of treatment its modification :Aim of treatment its modification : radio iodine destroys thyroid cell and as radio iodine destroys thyroid cell and as in thyroidectomy , reduces the mass of in thyroidectomy , reduces the mass of functioning thyroid tissue to below a functioning thyroid tissue to below a critical level.critical level.

Advantages :Advantages : Safe , simpleSafe , simple Less expensive than operationLess expensive than operation No prolonged drug therapy.No prolonged drug therapy.

Disadvantages :Disadvantages : 1. No reliable method of estimating the exact dose1. No reliable method of estimating the exact dose2. Complication of irradiation to the working 2. Complication of irradiation to the working

physicians.physicians.3. Delayed action :3. Delayed action : As its effect appears after 2 – 3 months , As its effect appears after 2 – 3 months ,

therefore if the symptoms are severe anti therefore if the symptoms are severe anti thyroid drugs are given during this periodthyroid drugs are given during this period

4. Incidence of thyroid insufficiency may reach 4. Incidence of thyroid insufficiency may reach 75% after 10 years.75% after 10 years.

Contraindication :Contraindication : Patient below 40y because of its potential Patient below 40y because of its potential

carcinogenic effect (20y or more later). carcinogenic effect (20y or more later). Pregnancy as it may lead to cretinism Pregnancy as it may lead to cretinism Lactation as it is excreted in milk.Lactation as it is excreted in milk.

Dose of radio iodine for Dose of radio iodine for treatment :treatment :

4 – 84 – 8 millicuries according to millicuries according to the size of the gland given in a the size of the gland given in a small amount of water or milk. small amount of water or milk. The dose can be repeated once The dose can be repeated once after 3 months.after 3 months.

N.B.N.B.Microcurie = 1/1000,000 of Microcurie = 1/1000,000 of curiecurie

MillicurieMillicurie = 1/1000 of = 1/1000 of curiecurie

3. Surgical treatment3. Surgical treatment Indications :Indications :

moderate and severe cases moderate and severe cases pressure symptomspressure symptoms 2ry toxic goitre 2ry toxic goitre suspicion of malignancy suspicion of malignancy failure of medical treatment or relapse after it failure of medical treatment or relapse after it retrosternal as medical treatment will retrosternal as medical treatment will

increase the size of gland and cause more increase the size of gland and cause more pressure symptoms.pressure symptoms.

Advantage :Advantage : rapid cure , low incidence of rapid cure , low incidence of recurrencerecurrence

Disadvantage :Disadvantage : Recurrence of thyrotoxicosis in about 5% of Recurrence of thyrotoxicosis in about 5% of

cases.cases. Complication of the operation.Complication of the operation.

Preoperative investigation :Preoperative investigation : 1. Indirect laryngoscope 1. Indirect laryngoscope 2. Thyroid anti body titres 2. Thyroid anti body titres 3. x-ray chest ( retrosternal 3. x-ray chest ( retrosternal

extension – calcification extension – calcification deviation of trachea ).deviation of trachea ).

4. Scanning 4. Scanning 5. Complete rest physically and 5. Complete rest physically and

mentally mentally 6. Sedation by luminal6. Sedation by luminal

7. Anti thyroid drug till B.M.R falls to 7. Anti thyroid drug till B.M.R falls to normal normal

8. 8. 15 days15 days before operation anti before operation anti thyroid thyroid

are stopped instead we give lugol’s are stopped instead we give lugol’s iodine 10 drops T.D.S to vascularity iodine 10 drops T.D.S to vascularity and make the gland tough.and make the gland tough.

Lugol`s Iodine = Lugol`s Iodine = 5%5% iodine in iodine in 10%10% KIsolutionKIsolution

9. Inderal may be used as B. 9. Inderal may be used as B. adrenergic blockers for severe adrenergic blockers for severe tachycardia . tachycardia .

Subtotal ThyroidectomySubtotal Thyroidectomy Anaesthesia :Anaesthesia : general endo – tracheal general endo – tracheal Position :Position : supine with sand bag behind the supine with sand bag behind the

shoulders to extent the neck shoulders to extent the neck Incision :Incision : kocher’skocher’s ( (collarcollar) incision in one of ) incision in one of

the lower creases of the neck it extends the lower creases of the neck it extends from the posterior border of one from the posterior border of one sternomastoid to the post. Border of the sternomastoid to the post. Border of the other. other.

Incision divides the skin and superficial Incision divides the skin and superficial fascia containing the platysma some prefer fascia containing the platysma some prefer to divide the platysma at a slightly higher to divide the platysma at a slightly higher level than the skin to obtain a good scar level than the skin to obtain a good scar

mobilization of the skin flaps:mobilization of the skin flaps: The upper to The upper to the level of upper border of thyroid cartilage the level of upper border of thyroid cartilage and the lower to level of manubrium.and the lower to level of manubrium.

Anterior jugular veins are divided Anterior jugular veins are divided between ligatures between ligatures

Opening the investing layer of deep Opening the investing layer of deep fascia in midline vertically. fascia in midline vertically.

Incising the sheath of pretracheal fascia Incising the sheath of pretracheal fascia in the midline in the midline

As a rule the larger lobe is dealt with As a rule the larger lobe is dealt with first.first.

Separation or division of infrahyoid Ms.Separation or division of infrahyoid Ms.In order to expose the thyroid the muscles In order to expose the thyroid the muscles

are divided in cases of :are divided in cases of : A. Big nodular goitre.A. Big nodular goitre.B. Toxic goitre to minimize manipulation.B. Toxic goitre to minimize manipulation.C. Malignant goitre.C. Malignant goitre.

They are divided near their upper They are divided near their upper end as their nerve supply comes from end as their nerve supply comes from below (from ansacervicalis) below (from ansacervicalis)

Devascularization :Devascularization : Ligation of Ligation of middle thyroid veinmiddle thyroid vein

(easily rupture with more bleeding) (easily rupture with more bleeding) its division makes mobilization of the its division makes mobilization of the gland easier.gland easier.

Ligation of Ligation of sup. Thyroid artery and sup. Thyroid artery and veinvein as near to the gland as possible as near to the gland as possible to avoid sup. Laryngeal n.to avoid sup. Laryngeal n.

Ligation of Ligation of inf. Thyroid arteryinf. Thyroid artery as far from as far from the gland as possible (away and laterally) the gland as possible (away and laterally) to avoid the recurrent laryngeal n.to avoid the recurrent laryngeal n.

Legation of Legation of inf. Thyroid veininf. Thyroid vein in front of in front of trachea.trachea.

Removal of required portion of gland Removal of required portion of gland leaving post medial part to protect leaving post medial part to protect parathyroid and recurrent nerves. parathyroid and recurrent nerves.

In case of In case of simple goitresimple goitre , it is advisable to , it is advisable to leave about equal to normal lobe on each leave about equal to normal lobe on each side but , in side but , in toxic goitretoxic goitre there are general there are general tendency to leave very little thyroid tissue tendency to leave very little thyroid tissue since the risk of recurrent thyrotoxicosis since the risk of recurrent thyrotoxicosis is greater than that of myxaedema the is greater than that of myxaedema the amount suggested is that which equals amount suggested is that which equals one third of normal lobe.one third of normal lobe.

Closure leaving a drain on each Closure leaving a drain on each side reaching the depth of wound side reaching the depth of wound behind the infrahyoid muscles.behind the infrahyoid muscles.

The platysma is closed with plain The platysma is closed with plain cat gut as a separate layer in cat gut as a separate layer in order to allow removal of the order to allow removal of the stitches of skin early. Skin is stitches of skin early. Skin is closed with interrupted silk closed with interrupted silk suture or with metal clips.suture or with metal clips.

The stitches or clips are removed The stitches or clips are removed after 3 – 4 days.after 3 – 4 days.

What are indications of What are indications of tracheastomy after tracheastomy after thyroidectomy ?thyroidectomy ?

1. Post operative oedema of 1. Post operative oedema of glottis.glottis.

2. Post operative deep 2. Post operative deep haemorrhage beneath pre-haemorrhage beneath pre-tracheal M and not relieved by tracheal M and not relieved by re-opening of the wound.re-opening of the wound.

3. Bilateral injury of recurrent.3. Bilateral injury of recurrent.4. Tracheomalacia .4. Tracheomalacia .

Complications of thyroidectomyComplications of thyroidectomyLocal complications :Local complications :1. Hemorrhage 1. Hemorrhage 2. Liquefying hematoma2. Liquefying hematoma3. Wound infection (uncommon)3. Wound infection (uncommon)4. Tracheitis4. Tracheitis5. Phemothorax and mediastinal emphysema5. Phemothorax and mediastinal emphysema6. Air embolism6. Air embolism7. Unsightly scar7. Unsightly scar8. Glottic oedema8. Glottic oedema9. Tracheal collapse9. Tracheal collapse10. N. injuries : 10. N. injuries :

R. laryngeal n.R. laryngeal n. Sup. Laryngeal n.Sup. Laryngeal n. Cervical sympathetics ( Horner’s Cervical sympathetics ( Horner’s

syndrome).syndrome).

Endocrine :Endocrine :1. Tetany1. Tetany2. Thyrotoxic crisis 2. Thyrotoxic crisis 3. Recurrent thyrotoxicosis 3. Recurrent thyrotoxicosis 4. Progressive exophthalmos4. Progressive exophthalmos5. Myxaedema 5. Myxaedema

1. Tetany1. Tetany- - It is due to removal of all parathyroids It is due to removal of all parathyroids - It is rare but permanent.- It is rare but permanent.- It is frequently due to scheme - It is frequently due to scheme

resulting from ligation of all vessels of resulting from ligation of all vessels of the thyroid and is temporary because the thyroid and is temporary because the parathyroids regain new blood the parathyroids regain new blood supply from the neighboring vessels supply from the neighboring vessels

Treatment :Treatment :- - Calcium gluconate 10 cc 10% daily Calcium gluconate 10 cc 10% daily

until improvement occurs.until improvement occurs.- In permanent cases oral long therapy - In permanent cases oral long therapy

is given . is given .

2. Thyroxic crisis2. Thyroxic crisis- - It is due to flooding of the circulation It is due to flooding of the circulation

with thyroxin after operation.with thyroxin after operation.- Usually in adequate preoperative - Usually in adequate preoperative

preparation and excessive manipulation preparation and excessive manipulation during the operation are the cause of during the operation are the cause of this crisis this crisis

It is characterized by :It is characterized by : 1. Marked irritability 1. Marked irritability 2. Marked sweating.2. Marked sweating.3. Severe tachycardia.3. Severe tachycardia.4. Hyperthermia 4. Hyperthermia 5. Heart failure in neglected cases 5. Heart failure in neglected cases

Treatment :Treatment :1. Sedation : morphia 1. Sedation : morphia 2. anti-pyretic : cold compresses and 2. anti-pyretic : cold compresses and

largactil largactil 3. Glucose 5% I.V for increased metabolic 3. Glucose 5% I.V for increased metabolic

raterate4. 5 c.c. Lugol`s iodine in one bottle of 4. 5 c.c. Lugol`s iodine in one bottle of

glucose I.Vglucose I.V5. A.C.T.H and cortisone may needed in 5. A.C.T.H and cortisone may needed in

severe cases.severe cases.6. Anti thyroid drugs should be given in 6. Anti thyroid drugs should be given in

big doses big doses 7. Inderal is given to control tachycardia 7. Inderal is given to control tachycardia

Cancer thyroidCancer thyroid 1. Precancerous conditions1. Precancerous conditions2. Pathological types2. Pathological types3. Clinical features.3. Clinical features.4. Investigations 4. Investigations 5. Treatment 5. Treatment

1. Precancerous conditions1. Precancerous conditions1. 1. Adenoma Adenoma of the thyroidof the thyroid2.2. Nodular Nodular goitre specially in endemic areas goitre specially in endemic areas

(solitary nodular is more liable to undergo malig.) (solitary nodular is more liable to undergo malig.) usually gives usually gives follicularfollicular type. type.

3. Previous3. Previous irradiation irradiation of the neck in children (never of the neck in children (never in adult) of enlarged thymus or T.B lymphadenitis in adult) of enlarged thymus or T.B lymphadenitis usually gives usually gives papillary papillary type.type.

4. 4. Genetic factorsGenetic factors : sometimes : sometimes medullarymedullary carcinoma carcinoma run in families.run in families.

5. Carcinoma of thyroid is extremely rare with 5. Carcinoma of thyroid is extremely rare with toxictoxic goitregoitre..

2. Pathological Types2. Pathological Types PapillaryPapillary adenocarcinoma 85% adenocarcinoma 85% - Occult. Occult. - Intra-thyroidal. Intra-thyroidal. - Extra-thyroidal.Extra-thyroidal. It is commonest type , met with any It is commonest type , met with any

age , common in children specially with age , common in children specially with previous irradiation of the neck. It is previous irradiation of the neck. It is usually has good prognosis. It is formed usually has good prognosis. It is formed of delicate branching C.T covered by of delicate branching C.T covered by one or several layers of cuboidal cells one or several layers of cuboidal cells small calcified areas , called small calcified areas , called “Psammoma bodies” are seen and may “Psammoma bodies” are seen and may help in differentiation from benign. help in differentiation from benign.

It is characterized by :It is characterized by : 1. Low grade malignancy.1. Low grade malignancy.2. Slow growth it may remain 2. Slow growth it may remain

stationary with or without stationary with or without metastases for many years.metastases for many years.

3. Early lymphatic spread to deep 3. Early lymphatic spread to deep cervical L.N.cervical L.N.

4. The affected L.N reach a big size 4. The affected L.N reach a big size while the primary is small “lat while the primary is small “lat aberrant thyroid T.”aberrant thyroid T.”

5. The papillary T. has a small or no 5. The papillary T. has a small or no radio-iodine uptake.radio-iodine uptake.

Treatment : Treatment : Total thyroidectomy with Total thyroidectomy with

unilateral or bilateral block unilateral or bilateral block dissection of Lymph Nodes. dissection of Lymph Nodes.

Thyroid extract is given post Thyroid extract is given post operatively in big doses as operatively in big doses as replacement therapy to suppress replacement therapy to suppress the T.S.H in trial to inhibit the T.S.H in trial to inhibit further of the glandfurther of the gland..

2. Follicular adenocarcinoma 10 %2. Follicular adenocarcinoma 10 % It is usually common in endemic nodular goitres met It is usually common in endemic nodular goitres met

with any age usually between 40 – 60 years. It forms with any age usually between 40 – 60 years. It forms grey , non encapsulated mass with varying degree of grey , non encapsulated mass with varying degree of differentiation. The well differentiated type is usually differentiation. The well differentiated type is usually referred as “malignant adenoma” , and may remain referred as “malignant adenoma” , and may remain without metastases for many years. While , the without metastases for many years. While , the undifferentiated tumors grow more rapidly in size , undifferentiated tumors grow more rapidly in size , spread mainly by BI. But lymphatic is also common.spread mainly by BI. But lymphatic is also common.

The follicular tumors in which invasion is minimal are The follicular tumors in which invasion is minimal are termed termed “non-invasive“non-invasive” and those in which invasion is ” and those in which invasion is moderate or marked are termed “moderate or marked are termed “invasiveinvasive”.”.

The follicular T. has a large radio-iodine uptake.The follicular T. has a large radio-iodine uptake.Treatment :Treatment : Total thyroidectomy with block dissection. Total thyroidectomy with block dissection. In case of 2ryies scanning for it with radio active iodine. In case of 2ryies scanning for it with radio active iodine. If active : radio active iodine ablationIf active : radio active iodine ablation If inactive deep x-ray therapy.If inactive deep x-ray therapy.

3. Anaplastic Carcinoma 3%3. Anaplastic Carcinoma 3% It usually occurs in old age group.It usually occurs in old age group. It grows very rapidly to infiltrate the thyroid It grows very rapidly to infiltrate the thyroid

and the surrounding T.and the surrounding T. two types are recognised : the small cell two types are recognised : the small cell

and giant cell types.and giant cell types. The The small cellsmall cell type may be mistaken for a type may be mistaken for a

lymphosarcemalymphosarcema , while the , while the giant cellgiant cell type type simulate on anaplastic simulate on anaplastic fibrosarcomafibrosarcoma..

The tumor spreads rapidly by the blood and The tumor spreads rapidly by the blood and lymph and kills the patient in a short time.lymph and kills the patient in a short time.

It is of bad prognosesIt is of bad prognoses90% of patient are dead within 1 year.90% of patient are dead within 1 year.10 % of patient are dead within 3 years10 % of patient are dead within 3 yearsTreatment Treatment Surgery has little or no place , but deep x-Surgery has little or no place , but deep x-

ray therapy chemotherapy, tracheostomy ray therapy chemotherapy, tracheostomy may be needed.may be needed.

4. Medullary Carcinoma 2 - 4%4. Medullary Carcinoma 2 - 4% It is rare tumors , a rise from It is rare tumors , a rise from para-follicularpara-follicular

cells “cells “CC” cells which secrete ” cells which secrete calcitonincalcitonin.. The malignant cells contains amyloid.The malignant cells contains amyloid. The tumors are solid , hard , not hormone The tumors are solid , hard , not hormone

dependent and do not take up radio-iodinedependent and do not take up radio-iodine High level of serum calcitonin are produced High level of serum calcitonin are produced

by many medullary carcinoma.by many medullary carcinoma. DiarrheaDiarrhea is a feature of 30% of cases , this is is a feature of 30% of cases , this is

may due to 5 HT produced by malignant may due to 5 HT produced by malignant cells.cells.

The tumors present usually in 50 – 70 age The tumors present usually in 50 – 70 age group but there is younger group which group but there is younger group which presents in childhood or before 30 years with presents in childhood or before 30 years with family history and is associated with family history and is associated with hyperparathyroidismhyperparathyroidism and and pheochromocytomapheochromocytoma , a combination known as, a combination known as Sipple’s Syndrome Sipple’s Syndrome..

The prognosis depends upon the absence or The prognosis depends upon the absence or presence of L.N. metastases.presence of L.N. metastases.

N.B. N.B. Multinodular goitre is a benign Multinodular goitre is a benign

lesion it causes post. lesion it causes post. Displacement of carotid Displacement of carotid pulsation but , malignant goitre pulsation but , malignant goitre will lead to compression and will lead to compression and obliteration of it without carotid obliteration of it without carotid displacement.displacement.

3. Clinical features3. Clinical features 1. Features 1. Features SSuspicious of malignancy : a uspicious of malignancy : a

solitary nodule in the thyroid gland.solitary nodule in the thyroid gland.2. Features 2. Features SSuggestive of malignancy : uggestive of malignancy :

Rapid growth in size.Rapid growth in size. Hard consistency.Hard consistency. Fixity.Fixity. Pressure manifestations :Pressure manifestations :On recurrent : hoarseness of voiceOn recurrent : hoarseness of voiceOr trachea : dyspnea.Or trachea : dyspnea.On esophagus: dysphagiaOn esophagus: dysphagiaOn carotid : absence of carotid On carotid : absence of carotid

pulsation ( Berry`s sign ) pulsation ( Berry`s sign )

Pain indicate infiltration of nerves , Pain indicate infiltration of nerves , especially which referred to the ear which especially which referred to the ear which passes along auricular branch of the passes along auricular branch of the vagus (Arnold’s nerve).vagus (Arnold’s nerve).

Increased vascularity.Increased vascularity. Cold adenoma.Cold adenoma.

3. Features indicating 3. Features indicating SSure ure malignancy :malignancy :

A. A. presence of 2ry metastases presence of 2ry metastases B. positive biopsy and paraffin section. Open B. positive biopsy and paraffin section. Open

biopsy is not recommended in anaplastic type for biopsy is not recommended in anaplastic type for fear of fungation , needle biopsy here is better.fear of fungation , needle biopsy here is better.

C. Absent carotid pulsation C. Absent carotid pulsation D. Recent hoarseness of voiceD. Recent hoarseness of voice

4. Investigations4. Investigations Plain x-ray of neck and chest Plain x-ray of neck and chest ScanningScanning LaryngoscopyLaryngoscopy Biopsy and paraffin section .Biopsy and paraffin section . X-ray of skull, chest, vertebra for 2ry X-ray of skull, chest, vertebra for 2ry

which is ostohytics.which is ostohytics. Ultrasonography.Ultrasonography. Aspiration biopsy cytology ( ABC)Aspiration biopsy cytology ( ABC) now it is becoming more widely appliednow it is becoming more widely applied DNA content to distinguish between DNA content to distinguish between

follicular adenoma and follicular follicular adenoma and follicular carcinoma.carcinoma.

ThyroiditisThyroiditis 1.1. Acute thyroiditis (Rare) :Acute thyroiditis (Rare) : it is rare , it it is rare , it

may arise in the course of infectious may arise in the course of infectious fevers e.g. scarlet fever and typhoid and fevers e.g. scarlet fever and typhoid and is commoner in goitrous than normal is commoner in goitrous than normal glands. The gland becomes enlarged , glands. The gland becomes enlarged , hot and tender with deep diffuse pain in hot and tender with deep diffuse pain in the neck , often referred to the ear , the neck , often referred to the ear , occiput or jaw.occiput or jaw.

Treatment : antibiotics , local foments Treatment : antibiotics , local foments and drainage of pus if suppuration and drainage of pus if suppuration occurs. (rare)occurs. (rare)

2. Subacute thyroiditis (De Quervain’s disease) :2. Subacute thyroiditis (De Quervain’s disease) : it is a rare condition which as supposed to be caused it is a rare condition which as supposed to be caused

by the virus of mumps. Onset : acute with pain , fever by the virus of mumps. Onset : acute with pain , fever , malaise and sweating. The gland : slightly enlarged , malaise and sweating. The gland : slightly enlarged firm , tender.firm , tender.

Diagnosis depend upon :Diagnosis depend upon : increased S.Rincreased S.R normal leucocytic count normal leucocytic count absent thyroid antibodies.absent thyroid antibodies. Not radio-iodine uptake by gland.Not radio-iodine uptake by gland. increased serum gamma globulin.increased serum gamma globulin. The disease is self limited and resolution occurs The disease is self limited and resolution occurs

in few months.in few months.

3. Lymphadenoid goitre “Hashimoto’s 3. Lymphadenoid goitre “Hashimoto’s disease”disease”

It is auto immune disease , the patient is It is auto immune disease , the patient is sensitized to her own thyroglobulin. The result sensitized to her own thyroglobulin. The result is destruction of thyroid tissue and its is destruction of thyroid tissue and its replacement with lymphoid tissue.replacement with lymphoid tissue.

It usually affects females at menopauseIt usually affects females at menopause The gland : The gland :

Moderate enlargement.Moderate enlargement. Rubbery in consistency.Rubbery in consistency. Lobulated not nodular.Lobulated not nodular. More defined border than nodular.More defined border than nodular.

Hypothyroidism is common and may end in Hypothyroidism is common and may end in myxaedema.myxaedema.

Liver and spleen may enlarged.Liver and spleen may enlarged.

Diagnosis Diagnosis depends on clinically and depends on clinically and laboratory lest :laboratory lest :

increased serum gamma globulin fractions.increased serum gamma globulin fractions. increased titre of thyroid antibodies.increased titre of thyroid antibodies. +ve precipitation tests on the patient’s serum.+ve precipitation tests on the patient’s serum.

Treatment Treatment Full replacement therapy of T4 for life as Full replacement therapy of T4 for life as

hypothyroidism is inevitablehypothyroidism is inevitable Excision is not advised due to high Excision is not advised due to high

possibilities of post operative myxoedema possibilities of post operative myxoedema which is common.which is common.

If there are pressure symptoms division of If there are pressure symptoms division of thyroid isthmus is indicated.thyroid isthmus is indicated.

Subtotal is done for cosmetic disease rarely.Subtotal is done for cosmetic disease rarely. Irradiation is contraindicated of it is sensitive.Irradiation is contraindicated of it is sensitive.

4. Reidel’s thyroiditis “Woddy thyroid”4. Reidel’s thyroiditis “Woddy thyroid” It is very rare condition of unknown etiology.It is very rare condition of unknown etiology. The thyroid tissue is replaced by cellular fibrous The thyroid tissue is replaced by cellular fibrous

tissue which infiltrates through the capsule into tissue which infiltrates through the capsule into adjacent muscles , para tracheal C.T and adjacent muscles , para tracheal C.T and carotid sheath.carotid sheath.

Gland : enlarges with progressive Gland : enlarges with progressive indurationinduration , till , till it become it become stony hardstony hard in consistency and in consistency and fixedfixed..

Adhesion are extensive and pressure symptoms Adhesion are extensive and pressure symptoms are frequent.are frequent.

It affects young adult of both sexes.It affects young adult of both sexes. Thyroid function remains normal.Thyroid function remains normal. Serum P.B.I , radio – iodine uptake are normal.Serum P.B.I , radio – iodine uptake are normal. The D.D from anaplastic carcinoma can only be The D.D from anaplastic carcinoma can only be

made by biopsy.made by biopsy.

Treatment :Treatment : 1. division of isthmus is usually 1. division of isthmus is usually

needed to relieve the pressure on the needed to relieve the pressure on the trachea.trachea.

2. thyroidectomy is not possible as the 2. thyroidectomy is not possible as the gland is marked adherent to gland is marked adherent to neighboring structures.neighboring structures.

3. radio therapy is ineffective.3. radio therapy is ineffective.

What are the causes of diffuse What are the causes of diffuse enlargement of thyroid ?enlargement of thyroid ?

Physiological goitre little Physiological goitre little enlargement and enlargement and soft.soft.

Colloid goitre may huge , always Colloid goitre may huge , always elasticelastic

Primary thyrotoxicosis may be Primary thyrotoxicosis may be minimal and soft.minimal and soft.

Hashimoto’s disease very Hashimoto’s disease very firm.firm. Riedel’s diseases Riedel’s diseases woodywoody thyroid. thyroid.

What are the causes of painful thyroid What are the causes of painful thyroid swellings ? swellings ?

1. Subacute thyroiditis.1. Subacute thyroiditis.2. Hemorrhage in a cystadenoma.2. Hemorrhage in a cystadenoma.3. Infiltrated malignant thyroid.3. Infiltrated malignant thyroid.