Head & NeckPharynx & Larynx

Mohamed Zaitoun

Assistant Lecturer-Diagnostic Radiology Department , Zagazig University Hospitals

EgyptFINR (Fellowship of Interventional

Neuroradiology)-Switzerlandzaitoun82@gmail.com

Knowing as much as possible about your enemy precedes successful battle

and learning about the disease process precedes successful management

Pharynx & Larynxa) Nasopharynxb) Hypopharynx, Larynxc) Parapharyngeal Space

Normal anatomy of the pharynx, AP air-contrast image shows that the true anatomic dividing line between the oropharynx and hypopharynx is the obliquely coursing pharyngoepiglottic fold (curved arrows), the vallecular pouches (V) are symmetric, divided by the median glossoepiglottic fold (open arrows), the free margin (straight solid arrows) of the epiglottis projects superior to the valleculae, the hypopharynx consists of the piriform sinuses (P), the posterior pharyngeal wall, and the postcricoid region, the lateral wall of the piriform sinus demarcates the lateral margin (solid arrowheads) of the hypopharynx, the entire bulk of the larynx pressing on the anterior pharynx creates a coated mucosal surface known as the “postcricoid line” (open arrowheads)

Normal anatomy of the pharynx, on a lateral air-contrast image, the slightly nodular surface of the base of the tongue (bot) is superior to the valleculae (V), although the hyoid bone (H) moves and changes its position relative to the pharynx during swallowing, it can be used as a proxy landmark to delineate the dividing line between the oropharynx and hypopharynx, the free margin (black arrows) of the epiglottis (E) projects posterior and superior to the vallecula, the aryepiglottic fold (white arrow) covers the posterior surface of the arytenoid cartilage (a), the prevertebral soft tissues (PV) lie between the posterior wall of the oropharynx and hypopharynx and the vertebral column, P = piriform sinuses

a) Nasopharynx :1-Thornwaldt Cyst2-Retropharyngeal Abscess3-Juvenile Angiofibroma4-Squamous Cell Carcinoma

1-Thornwaldt Cyst :a) Incidenceb) Radiographic Features

a) Incidence :-Cystic midline nasopharyngeal notochordal

remnant (3% of population)-May occasionally become infected-Age : 15 to 30 years

b) Radiographic Features :-Hemispherical soft tissue density seen on

lateral plain films-Typical cystic appearance by CT and MRI-Location : midline, same level as adenoids

T1 T2 T1+C

T1 T2 T1+C

With Rathke’s cleft cyst

2-Retropharyngeal Abscess :a) Etiologyb) Radiographic Featuresc) Differential Diagnosis

a) Etiology :-Dental disease, pharyngitis, penetrating

trauma, vertebral osteomyelitis-Organism : Staphylococcus, Streptococcus,

anaerobes, Mycobacterium tuberculosis (TB)

b) Radiographic Features :1-Plain Radiography :-Soft tissue swelling posterior to the pharynx-Widened retropharyngeal space2-CT :-Gas-Necrotic tissue and edema appear hypodense-Stranding of fat-Rim enhancement with contrast

Retropharyngeal abscess in a 3-year-old girl with fever and throat pain, (a) Lateral neck radiograph shows diffuse prevertebral soft tissue swelling (arrows), (b) CT+C demonstrates a mildly enhancing, thick-walled retropharyngeal fluid collection (arrow), these findings are indicative of an abscess

Retropharyngeal abscess in a 30-year-old man who presented with worsening odynophagia and dysphagia, lateral image from a barium pharyngographic study demonstrates marked widening of the prevertebral soft-tissue stripe (PV) caused by a soft-tissue mass containing small foci of gas (arrowheads)

Retropharyngeal abscess, CT+C shows a large retropharyngeal fluid collection (arrows) with peripheral rimlike enhancement

Retropharyngeal abscess, CT+C shows a peripherally enhancing left RPS fluid collection (large arrow) under tension, heterogeneous enhancement is present in the right RPS (small arrow) consistent with inflammatory change

3-MRI :*T1 : central low to intermediate signal*T2 : central high signal *T1+C : peripheral enhancement *DWI : restricted

T1 T2 T1+C

T1+C DWI

c) Differential Diagnosis :-Prevertebral soft tissue mass in a child on lateral

cervical X-ray :1-Trauma / hematoma2-Abscess3-Lympahtic malformation4-Lymphoma5-Nasopharyngeal rhabdomyosarcoma6-Neuroblastoma

-Prevertebral soft tissue mass in an adult on lateral cervical X-ray :

1-Trauma / hematoma2-Abscess3-Postcricoid carcinoma4-Chordoma5-Pharyngeal pouch (air fluid level)6-Retropharyngeal goiter

3-Juvenile Angiofibroma :a) Incidenceb) Clinical Picturec) Radiographic Featuresd) Differential Diagnosis

a) Incidence :-Vascular tumor of mesenchymal origin-Most frequent benign nasopharyngeal

tumor in adolescents (age : 10 to 20)-Males only, however some cases were

reported in females

b) Clinical Picture :-Presentation is typically with obstructive

symptoms, epistaxis and chronic otomastoiditis due to obstruction to the eustachian tube

-Patients may present with life threatening epistaxis

-On examination it may be seen as a pale reddish blue mass

c) Radiographic Features :-Usually large soft tissue mass causing local bony

remodeling-Centered on the sphenopalatine foramen (which

is often widened) and typically bowing the posterior wall of the maxillary antrum anteriorly (Holman-Miller sign, also called antral sign) 

-Highly vascular :Intense enhancement by CT and MRIMRI : very hyperintense on T2, flow voidsTumor blush by angiography-Embolization before resection :Main supply from ECA particularly maxillary arteryMay have supply from ICA

Homogenously enhancing mass lesion centered at sphenopalatine foramen (widened by the mass, shown by black arrows), extending into nasopharynx (yellow arrow) and pterygopalatine fossa (red arrow), the mass also fills ipsilateral nasal cavity, pushing the septum to left

Bowing of the posterior wall of the maxillary antrum (Holman Miller or antral sign; red arrows)

Juvenile angiofibroma in a 15-year-old boy with recurrent epistaxis, axial unenhanced CT image depicts a homogeneous mass centered in the sphenopalatine foramen, the mass extends into the nasal cavity and widens the pterygopalatine fossa)

CT+C shows a large heterodense destructive soft tissue lesion seen in the superior postero-lateral wall of the right nasal cavity, extending into the nasopharynx and adjacent pterygopalatine fossa, right pre-maxillary space causing bowing of the posterior antral wall: The characteristic Holman Miller sign (yellow arrow) with erosion/ destruction of adjacent bones

(a) Axial CT shows a tumor that arises from the right pterygoid plate and grows into and widens the pterygopalatine fossa (asterisk), the tumor then grows anteromedially through the sphenopalatine foramen (white arrow), laterally through the pterygomaxillary fissure (black arrow), and posteriorly into the Vidian canal (arrowheads), (b) Coronal CT demonstrates destruction of the pterygoid plate just posterior to the pterygopalatine fossa

A comparison of axial unenhanced (a) and contrast-enhanced (b) T1 shows avid enhancement of the mass (arrows in b), note the flow voids in the pterygopalatine fossa (arrowheads in b),

(a) T1 shows a large, well-defined mass (arrow) in the region of the pterygo-maxillary fissure and sphenopalatine foramen on the right side with a heterogenous intensity, (b) T2 shows a large, well-defined mass in the region of the pterygo-maxillary fissure and spheno-palatine foramen on the right side with heterogenous intensity, tiny flow voids are noted within the lesion (yellow arrows) consistent with hypervascularity

(a) Axial gradient echo and (b) axial T2 of a left-sided tumor growing anteriorly into the nasal cavity (black arrow), dislocating the ipsilateral maxillary sinus anteriorly (white arrow) and growing into the masticator space (black arrowhead), notice also growth into the broadened Vidian canal (white arrowheads), the rich vascularity of the tumor gives rise to the typical small dotted flow void

Right ECA angiogram shows the feeding internal maxillary artery (arrow) and the hypervascular lesion (arrowheads)

d) Differential Diagnosis : Nasopharyngeal mass1-Adenoid Hypertrophy2-Trauma , hematoma3-Infection , abscess 4-Benign Neoplasm :Angiofibroma , antrochoanal polyp5-Malignant Neoplasm :-Nasopharyngeal carcinoma-Lymphoma-Rhabdomyosarcoma-Plasmacytoma-Direct extension of paranasal sinus tumor6-Encephalocele :-Midline defect on skull base with herniation of

meninges and brain

4-Squamous Cell Carcinoma :a) Incidenceb) Locationc) Stagingd) Radiographic Featurese) Differential Diagnosis

a) Incidence :-SCC accounts for 80%-90% of malignant

tumors in the nasooropharynx (lymphoma : 5%, rare tumors : adenocarcinoma, melanoma & sarcoma)

-Strongly associated with Epstein Barr virus (EBV)

b) Location :1-Nasopharynx :-Tumors most commonly arise from lateral

pharyngeal recess (fossa of Rosenmeller)2-Oropharynx :-Palate-Tonsil-Tongue, pharyngeal wall-Lips, gingiva, floor of mouth

Fossa of Rosenmeller

c) Staging :*T :Tis : carcinoma in situT1 : tumor confined to 1 site of nasopharynx or no

tumor visibleT2 : tumor involving 2 sites (both posterosuperior

and lateral walls)T3 : extension of tumor into nasal cavity or

oropharynxT4 : tumor invasion of skull, cranial nerve

involvement or both

*N :N0 : clinically positive nodeN1 : single clinically positive homolateral node ≤3

cm in diameterN2 : single clinically positive homolateral node >3

cm but not >6 cm in diameterN3 : node >6 cm*M :M0 : no distant metastasesM1 : distant metastases

d) Radiographic Features :1-CT :-Asymmetry of soft tissues, primarily infiltrating

carcinomas produce only slight asymmetry-Mass, ulceration & infiltrating lesion2-MRI :*T1 : typically isointense to muscle *T2 : isointense to somewhat hyperintense to muscle,

fat saturation is helpful, fluid in the middle ear is a helpful marker

*T1+C : prominent heterogeneous enhancement is typical

Squamous cell carcinoma of the nasopharynx, CT+C shows an abnormal soft-tissue mass with relatively uniform contrast enhancement filling the left lateral fossa of Rosenmueller

The configuration of NPC is almost always asymmetric as seen in this contrast enhanced, axial T1 weighted fat saturation MRI image

T1+C shows small NPC (short arrows) centered in left Rosenmeller fossa (long arrow), which is the most common site for this cancer, and involving posterior wall, tumor is confined to nasopharynx (T1), and there is small metastatic left retropharyngeal node (curved arrow)

Nasopharyngeal carcinoma (NPC) with parapharyngeal extension (T2), T1+C shows NPC (white arrows) with left parapharyngeal extension and involvement of parapharyngeal fat space, note normal levator palatini muscle (red arrow), tensor palatini muscle (blue arrow), pharyngobasilar fascia (black arrow), and fat space (yellow arrow) on normal right side

Nasopharyngeal carcinoma with prevertebral extension (T2), T1+C shows nasopharyngeal carcinoma (straight arrows) with extensive spread predominantly posteriorly into longus muscles (arrowheads) and clivus (curved arrows)

NPC with skull base foraminal invasion, (a) Coronal T1+C shows NPC (straight arrows) with skull base invasion at foramen ovale (arrowhead) with invasion into cavernous sinus (curved arrow), (b) Coronal T1+C shows invasion of NPC (straight arrows) into foramen lacerum (arrowheads), where it encases carotid artery and extends into cavernous sinus (curved arrow), (c) Axial T1+C shows NPC invading pterygopalatine fossa (circle), pterygomaxillary fissure (arrow), and vidian canal (arrowhead)

e) Differential Diagnosis :-The differential for a small mass confined

to the mucosal space includes : 1-Prominent but normal adenoidal tissue2-Nasopharyngeal lymphoma3-Low grade / early other primary

nasopharyngeal malignancies

-The differential for a larger mass with involvement of base of skull includes all of the above with the addition of the following:

1-metastases2-Chordoma3-Chondrosarcoma4-Meningioma5-Even pituitary macroadenoma

b) Hypopharynx, Larynx :1-Vocal Cord Paralysis2-Laryngocele3-Laryngeal Trauma4-Benign Laryngeal Tumors5-Laryngeal Carcinoma6-Postsurgical Larynx

**Anatomy of the larynx :a) Laryngeal Cartilagesb) Laryngeal Ventricular Complex (LVC)c) Anterior and Posterior Commissured) The Paraglottic Space (PLS) and the Pre-

Epiglottic Space (PES)

a) Laryngeal Cartilages :-The larynx extends from the tip of epiglottis to the inferior

margin of the cricoid cartilage-The epiglottis, thyroid, cricoid and the paired arytenoid

cartilages are the four principal laryngeal cartilages1-The Epiglottis :-Is the superiormost, midline leaf-shaped cartilage, it has a

free margin and a fixed portion (stem)-The hyoepiglottic ligament attaches the free epiglottic

margin to the hyoid bone and the thyroepiglottic ligament attaches the epiglottic stem to the inner surface of the thyroid cartilage at a caudal level

-The free epiglottic margin appears before the hyoid is visualized  

2-The Thyroid Cartilage :-Has two laminae fused anteriorly, and

enlarged posteriorly, to form the superior and inferior cornua

-The superior cornua provide attachment to the thyrohyoid ligament and the inferior cornua articulate medially with the sides of the cricoid at the cricothyroid joint

3-The Cricoid Cartilage :-Is the inferiormost ring-shaped laryngeal cartilage

and the foundation of the larynx

4-The Paired Arytenoid Cartilages :-Sit along the upper margin of the cricoid lamina,

forming the cricoarytenoid joints- The vertical height of the arytenoid spans the

laryngeal ventricle-The apex of the arytenoid attaches the vestibular

ligament and corresponds to the level of the false cords

-The base of the arytenoids projects the vocal processes anteriorly, that attach the vocal ligament running along the inner margin of true vocal cords

Normal anatomy of the larynx (frontal view)

Normal anatomy of the larynx (lateral view)

Normal anatomy of the larynx, (a) supraglottic, tip of the epiglottis in the midline (arrow), (b) supraglottic, paired vallecullae (curved arrows) on either sides of hypoepiglottic ligaments (elbow arrow), epiglottis is seen in the midline (thin arrow)

Normal anatomy of the larynx, (a) supraglottic, the pre-epiglottic space (white asterisk) seen anterior to the epiglottis (thin arrow), note the aryepiglottic folds (bent arrows) and the piriform sinuses (notched arrows), (b) supraglottic, the stem of the epiglottis is seen attaching to the inner surface of the thyroid cartilage in the midline (thin arrow), the aryepiglottic folds (bent thick arrows), piriform sinuses (notched arrows) and paraglottic spaces (curved elbow arrows) are seen

Normal anatomy of the larynx, supraglottic, the tip of the arytenoid cartilages (double headed arrows) and the false cords (small arrows) are seen, the paraglottic spaces (curved elbow arrows) are seen deep to the false cords, this section represents the superior margin of the laryngeal ventricular complex

Normal anatomy of the larynx, glottic, the cricoarytenoid joints (straight arrows) are seen, the thyroarytenoid muscle forms the bulk of the true focal cords (block arrows) at this level, note the anterior commissure (elbow arrow) and the posterior commissure (curved arrow)

Normal anatomy of the larynx, subglottic, shows the cricoid ring

b) Laryngeal Ventricular Complex (LVC) :-This is the key component in organizing the larynx into the

supraglottis, glottis and subglottis-It comprises the false cords, true cords and intervening

laryngeal ventricle-The LVC is best identified on coronal images, the ventricle

itself is seen as a small air-filled outpouching between the false and true cords

-On axial images, the superior margin of the LVC is defined by a section through the apex of the arytenoids, the false cords and the fat-filled paraglottic spaces deep to the false cords

-The inferior margin is defined by a section through the true cords with the thyroarytenoid muscle and the cricoarytenoid joint

Coronal CT image through the larynx shows the epiglottis (thin arrow) , false cords (elbow arrow), laryngeal ventricle (thick arrow) , true cord (curved elbow arrow) and paraglottic space (black arrows)

Normal anatomy of the larynx, (a) supraglottic, the tip of the arytenoid cartilages (double headed arrows) and the false cords (small arrows) are seen, the paraglottic spaces (curved elbow arrows) are seen deep to the false cords, this section represents the superior margin of the laryngeal ventricular complex, (b) glottic, the cricoarytenoid joints (straight arrows) are seen, the thyroarytenoid muscle forms the bulk of the true focal cords (block arrows) at this level, note the anterior commissure (elbow arrow) and the posterior commissure (curved arrow)

c) Anterior and Posterior Commissure :-The anterior commissure is the midline

anterior meeting point of the true vocal cords

-The posterior commissure is the mucosal surface on the anterior surface of the cricoid cartilage between the arytenoid cartilages

Normal anatomy of the larynx, glottic, the cricoarytenoid joints (straight arrows) are seen, the thyroarytenoid muscle forms the bulk of the true focal cords (block arrows) at this level, note the anterior commissure (elbow arrow) and the posterior commissure (curved arrow)

d) The Paraglottic Space (PLS) and the Pre-Epiglottic Space (PES) :

-The PGS is located deep to the mucosal surfaces of the true and false cords and bound laterally by the thyroid and cricoid cartilages and is best seen on axial CT and MR sections through the supraglottis

-The pre-epiglottic space (PES) is a fat-filled space, rich in lymphatics. It is bound superiorly by the hyoepiglottic ligament, anteriorly by the thyrohyoid membrane, inferiorly by the thyroepiglottic ligament and posteriorly by the epiglottis

Normal anatomy of the larynx, supraglottic, (a) the pre-epiglottic space (white asterisk) seen anterior to the epiglottis (thin arrow), note the aryepiglottic folds (bent arrows) and the piriform sinuses (notched arrows), (b) the stem of the epiglottis is seen attaching to the inner surface of the thyroid cartilage in the midline (thin arrow), the aryepiglottic folds (bent thick arrows), piriform sinuses (notched arrows) and paraglottic spaces (curved elbow arrows) are seen, (c) the tip of the arytenoid cartilages (double headed arrows) and the false cords (small arrows) are seen, the paraglottic spaces (curved elbow arrows) are seen deep to the false cords, this section represents the superior margin of the laryngeal ventricular complex

(a) CT, (b) T1 show epiglottis (thin arrow), and the pre-epiglottic fat space (thick arrow), note the clear relationship of the base of the tongue (elbow arrow) with the epiglottis

1-Vocal Cord Paralysis :a) Incidenceb) Etiologyc) Radiographic Features

a) Incidence :-Can cause laryngeal dysfunction ranging from slight

hoarseness to life-threatening airway obstruction-The RLN is a branch of vagus nerve, the vagus

nerve descends with the carotid artery sheath into the upper mediastinum

-The RLNs enter the larynx posterior to the cricoarytenoid joints and innervate the intrinsic laryngeal muscles, the cricothyroid muscle is the only intrinsic laryngeal muscle not supplied by the RLN instead receiving its motor supply from the superior laryngeal nerve

Left anterior oblique dissected view shows the left vagus nerve exiting the skull base through the jugular foramen and descending through the neck posterolateral to the internal carotid arteries (ICA) and common carotid arteries (CCA), as the left vagus nerve passes anterolateral to the aortic arch, the left RLN branches off and passes below the arch posterior to the ligamentum arteriosum, it then ascends within the left tracheoesophageal groove to enter the larynx posteriorly at the level of the cricoarytenoid joint, the right vagus nerve descends posterolateral to the internal and common carotid arteries from the right jugular foramen, giving rise to the right RLN as it passes anterior to the right subclavian artery (SCA), the right RLN then passes posterior to the right brachiocephalic artery (BCA) before ascending to the larynx within the right tracheoesophageal groove, JV = jugular vein

At the level of the skull base, each vagus nerve is found within the posterolateral aspect of its respective jugular foramen (the pars vascularis) and posterolateral to the internal carotid artery.CCA = common carotid artery, JV = jugular vein

 At the level of the origin of the right subclavian artery (SCA), the right vagus nerve passes anterior to the subclavian artery, with the RLN crossing the mediastinum immediately below this point to reach the right tracheoesophageal groove. BCA Bifurc. = brachiocephalic artery bifurcation, CCA = common carotid artery, Tr = trachea

At the level of the aortic arch (AoA), the left vagus nerve gives rise to the RLN, which passes below the arch to reach the left tracheoesophageal groove. SVC = superior vena cava, Tr = trachea

The vagal nerves in the posterior fossa, axial heavily T2-weighted thin-slice MR image through the brainstem with the position of the nucleus ambiguus (white circles), the exit of the vagal nerves from the olivary sulcus (curved arrow), the cisternal segment of the vagal nerves (long arrow), and the pars nervosa of the jugular foramen (short arrow)

The course of the vagal nerves and recurrent laryngeal nerves, a Coronal MIP reformat showing the expected course of the vagal nerves bilaterally within the carotid sheath and proximal parts of the recurrent laryngeal nerves (dotted lines), the right recurrent laryngeal nerve branches just caudally to the right subclavian artery (short arrow) and crosses the right subclavian artery towards the tracheo-oesophageal groove, the left recurrent laryngeal nerve (long arrow) runs below the aortic arch, b CT+C of the skull base showing the jugular foramen with the jugular vein (long arrow), the pars nervosa (short arrow) and the internal carotid artery (*), c The carotid sheath with the ICA (A), the jugular vein (V) and the expected position of vagal nerve (*), d At the level of the subclavian arteries (S) the vagal nerves (long arrows) lie anteriorly in the upper mediastinum, at this level, the recurrent laryngeal nerves run more posteriorly in the tracheo-oesophageal groove (short arrows), e The left recurrent laryngeal nerve crosses the aortic arch from anterior to posterior (curved arrow) at the level of the aorto-pulmonary window (AP)

b) Etiology :-Innervation of vocal cord muscles is through the

recurrent laryngeal nerve of the vagus (CN X)-The left recurrent laryngeal nerve is more commonly

injured-Causes of paralysis include :1-Idiopathic2-Traumatic, surgical (thyroidectomy, carotid

endarterectomy and anterior approaches to the cervical spine)

3-Tumor : mediastinum, left hilum or lung apex (primary or mets)

4-Arthritis (degenerative changes of cricoarytenoid cartilage)

c) Radiographic Features :1-Abnormal movement of the involved cord2-Enlarged laryngeal ventricle & piriform sinus3-Flattening of false vocal cords & subglottic

angle4-Atrophy of the thyroarytenoid muscle (the

most characteristic finding is the result of atrophy of the thyroarytenoid muscle which makes up the bulk of the true cord) & posterior cricoarytenoid muscle

(a) Axial CT scan shows the normal appearance of the abducted vocal cords during quiet respiration, the level of the true cords is confirmed with visualization of the cricoarytenoid joints (arrow), (b) Axial CT scan shows the normal appearance of the adducted vocal cords during held respiration, as might be seen at thoracic CT

Normal appearance of the vocal cords, a Axial CT images during quiet breathing showing the anterior commissure (short arrow), the posterior commissure (long arrow) and the true vocal cords (T), b Image at the same level during breath-hold, c Normal appearance of the laryngeal ventricles on coronal reformat: right laryngeal ventricle (arrow); left true vocal cord (T); left false vocal cord (F)

Specific imaging characteristics of vocal cord paralysis (right side), a Widening of the right laryngeal ventricle (arrow), b Medial deviation and thickening of the right aryepiglottic fold (arrow), c Dilatation of the right piriform sinus (arrow)

Left RLN palsy, axial CT scan obtained at the level of the hypopharynx during quiet respiration shows left RLN palsy, note the distention of the ipsilateral piriform fossa with air (*) and the medially rotated, thickened ipsilateral aryepiglottic fold (arrow)

-PET / CT : asymmetric increased uptake in the normal cord due to compensation by and hypertrophy of the nonparalyzed muscles

-The following criteria should be taken into account when assessing abnormal FDG avidity in the larynx :

1-The side and location of increased metabolic activity relative to any CT findings that indicate VCP

2-History of recent chemotherapy treatment with vinka alkaloids (known to cause transient VCP)

3-The site of previous radiation treatment (a cause of acute and chronic neuropathy)

FDG-PET findings in VCP, a Non-contrast CT image showing medial deviation and thickening of the left aryepiglottic fold (*) indicative of left VCP, b Fused PET-CT showing FDG uptake in the right vocal cord (arrow) due to compensatory hypertrophy, this should not be confused with disease. Note the paramedian position of the left true vocal cord (T)

Right RLN palsy, (a) Fused PET/CT image at the level of the vocal cords shows abnormally increased muscle activity within the left vocal cord (*) and medialization of the right posterior cord margin (arrow), findings that are typical of right VCP, (b) Fused PET/CT image at the level of the hypopharynx demonstrates abnormal compensatory muscle activity on the left side (*) and a thickened, medially rotated right aryepiglottic fold (arrow), findings that are typical of right RLN palsy. At FDG PET/CT, unilateral VCP appears as asymmetric increased uptake in the normal cord due to compensatory activity and hypertrophy of the nonparalyzed muscles, with a lack of uptake in the paralyzed cord

2-Laryngocele :-Laryngocele is a saccular cyst that contains air and that

maintains communication with the laryngeal lumen -Dilatation of the laryngeal ventricle-Most commonly seen in glassblowers or patients with

chronic obstructive pulmonary disease (COPD)-Laryngoceles are classified as internal, external, or a

combination thereof based on their relationship with the thyrohyoid membrane :

a) Internal laryngocele remains confined within the larynx between the false vocal cord and the medial surface of the thyrohyoid membrane

b) External laryngocele extends upward and protrudes laterally through the thyrohyoid membrane

c) Combined laryngocele contains dilated internal and external components

-Saccular cysts and Laryngoceles are associated with laryngeal cancer, and these patients should be evaluated accordingly

-May be fluid or air filled

Internal External Combined

CT+C shows air filled internal laryngocele (arrow) on the right and mixed laryngocele (arrowhead) on the left side

CT showing a) external laryngocele as a cystic fluid filled mass (large arrows) on the left side with the trachea indicated by small arrow and b) laryngocele causing compression of the airway

External laryngocele, (a) AP from a barium pharyngogram demonstrates an air-filled structure in the left side of the neck (arrows) that is lateral to the pharyngeal structures, (b) Lateral image shows an air-filled external laryngocele (arrows) located anterior to the pharynx and just inferior to the mandible

3-Laryngeal Trauma :a) Etiologyb) Types

a) Etiology :1-Intubation : erosions, laryngomalacia &

stenosis2-Direct force : fractures-Displaced fractures of thyroid or cricoid

cartilage-Arytenoid dislocation-A false passage-Displacement of epiglottis

b) Types :1-Thyroid : longitudinal, paramedian, transverse or

comminuted fractures2-Cricoid : always breaks in 2 places, the posterior

component is often not clinically recognized3-Epiglottis : may be avulsed posteriorly and

superiorly4-Arytenoids : anterior and posterior dislocation

Fracture of the mid anterior thyroid cartilage

Acute comminuted fracture of both aspects of the cricoid cartilage

4-Benign Laryngeal Tumors :-Papilloma and hemangioma are the most

common tumors-Less common tumors : chondroma,

neurofibroma, fibroma, paraganglioma , rhabdomyoma, pleomorphic adenoma & lipoma

-Vocal cord polyps (not true tumors) are the most common benign lesions of the larynx

Vocal cord polyp

Axial CT image showing a right cord nodule (white arrow)

Axial CT image showing an anterior laryngeal polyp (black arrow)

5-Laryngeal Carcinoma :a) Pathologyb) Typesc) Staging d) Radiographic Features

a) Pathology :-Squamous Cell Carcinoma (SCC), 90%-Other,10% :1-Adenocarcinoma2-Metastases3-Tumors arising from supporting tissues of

larynx (chondrosarcoma, lymphoma, rare)4-Carcinosarcoma5-Adenocystic carcinoma

b) Types :1-Supraglottic, 30 %2-Glottic, 65 %3-Subglottic, 5 %

Axial CT scans through (a) false cords, (b) true cords, (c) subglottis to illustrate normal anatomy, (a) The tip of the arytenoids cartilages (white arrowhead) indicates the level of the false cords (open arrowhead) and also the superior aspect of the ventricular complex, (b) The anteriorly pointing vocal processes of the arytenoids (arrow) and the thyroarytenoid muscle (white arrowhead) are effacing the paraglottic fat within the wall of the larynx, this defines the level of the true cords and also the inferior aspect of the ventricular complex, the anterior and posterior (open arrowhead) commissures should only be represented by a thin mucosal layer, (c) There should be no soft tissue seen internal to the ring of the cricoid cartilage at subglottic level

Coronally reformatted CT demonstrates the supraglottis, glottis and subglottis as defined by the level of the ventricular complex (false cords (F), true cords (T) and intervening ventricle)

1-Supraglottic , 30 % :-May arise in the anterior compartment (epiglottis)

or the postero-lateral compartment (aryepiglottic fold and false cords)

-They often present in advanced stages, because symptoms (hoarseness, due to vocal cord involvement) do not occur until late

-Treated by supraglottic Laryngectomy or radiation therapy

a) Epiglottic SCC :-These are anterior midline cancers that primarily

invade into the PES-While the SCC arising from the mobile portion of

the epiglottis may spread from the PES further into the base of tongue and laterally into the PGS, those arising from the stem often invade the low PES and via the anterior commissure, reach the glottis or subglottis

-The primary sign of PES invasion at imaging is replacement of the normal fat by abnormal enhancing soft tissue

Pathway of spread of the of epiglottic mass

Supraglottic SCC, epiglottis, axial contrast CT image shows a lobulated enhancing epiglottic mass filling the pre-epiglottic space (black asterisk)

Supraglottic SC, epiglottis, axial contrast CT shows the epiglottic mass (arrowheads) filling the right vallecula (white asterisk), enlarged necrotic deep cervical node level II on the right side (elbow arrow)

b) Aryepiglottic Fold (AE fold) SCC :-These cancers present as exophytic or

infiltrative masses-They expand the AE fold and spread into

the PGS-They may spread further anteriorly into the

PES or posteriorly to invade the piriform sinus

Supraglottic mass arising from the aryepiglottic fold, line diagram shows a section through the aryepiglottic fold in the axial plane, the mass in the false cord is seen in red with pathways of spread in black curved arrows

Supraglottic SCC, aryepiglottic fold, a right aryepiglottic fold mass (thin white arrows) is seen invading into pre-epiglottic (white asterisk) and right paraglottic space (black asterisk) and narrowing the right piriform sinus (curved white arrow), note sclerosis of thyroid lamina (thin black arrow) with extralaryngeal tumor (white curved elbow arrows)

c) False Cord SCC :-These are lateral masses with a strong

predilection for submucosal spread into the PGS 

-More extensive tumor may destroy the thyroid cartilage and spread transglottically into the glottis and subglottis

-Tumor spread to the PGS on CT or MRI is seen as replacement of the normal paraglottic fat by the enhancing tumor tissue

Supraglottic mass arising from the false cord, line diagram shows a section through the false cord in the axial plane, the mass in the false cord is seen in red with pathways of spread in black curved arrows

Supraglottic SCC, false cord, axial contrast CT section through the false cords shows a mass within the right false cord and invading into the right PGS (black asterisk)

2-Glottic, 65 % :-Usually small when discovered (hoarseness is an early

finding)-Early symptoms, good prognosis-Glottic SCC commonly arise from the anterior half of the

vocal cord and spread into the anterior commissure, anterior commissural disease is seen on CT or MRI as soft tissue thickening of more than 1-2 mm

-From the anterior commissure, the tumor may spread further anteriorly into the contralateral cord and the thyroid cartilage or posteriorly into the posterior commissure, the arytenoids, cricoarytenoid joint and the cricoid cartilage

-The tumor may spread superiorly to access the PES and the PGS, or inferiorly to reach the subglottis, subglottic spread below the anterior commissure is seen as an irregular thickening of the cricothyroid membrane, tumor may gain access into the extra-laryngeal tissues through the cricothyroid membrane

Pathway of spread of glottic mass

Glottic SCC, axial contrast CT image shows a glottis mass in the left true cord reaching the anterior commissure (black asterisk), mild thickening of posterior commissure is noted (thick black arrow) with sclerosis of left arytenoid and left lamina of thyroid cartilage

Advanced SCC, axial CT+C shows a left cord mass (thin white arrows) reaching anterior commissure (asterisk), note the sclerosis of the left thyroid lamina and left cricoarytenoid joint (thin black arrows)

Advanced glottic SCC, axial CT+C at a caudal level shows the mass (thin white arrows) with disease in the in the posterior commissure (curved black arrow) and cricoid erosion (thick black arrow)

Advanced glottic SCC, axial CT+C through the subglottis shows the mass extending into the subglottis (thin white arrow) with irregularity of the cricothyroid membrane and extra-laryngeal spread (white elbow arrow)

3-Subglottic, 5 % :-Uncommon as an isolated lesion and usually seen

as an extension of glottic tumors-Poor prognosis because of early nodal metastases-Subglottic cancer is diagnosed if any tissue

thickening is noted between the airway and the cricoids ring

-Due to their late presentation, invasion of the cricoids cartilage, trachea and the cervical esophagus with extra-laryngeal spread are common findings in these patients at imaging

Subglottic SCC, axial contrast CT image through the subglottis shows a smooth well-defined enhancing mass is seen on the right side (thin white arrows) reaching anteriorly just below the anterior commissure (black asterisk)

Advanced subglottic SCC, axial CT image through the subglottis in another patient shows a circumferential subglottic mass with destruction of the cricoid and the thyroid cartilages (curved black elbow arrows) and extra-laryngeal spread of tumor (thin white arrows)

**N.B. : Transglottic SCC-Laryngeal SCC encroaching on both, the glottis

and supraglottis, with or without subglottic component and when the site of origin is unclear, is termed as transglottic tumor

-This tumor spread is frequently through the PGS and is readily identified on CT or MR imaging

-Transglottic carcinoma is frequently accompanied by metastatic lymphadenopathy

-Coronal images are particularly helpful in assessing transglottic extension of tumor

Transglottic mass, sagittal line diagram shows a large supraglottic mass (red color) spanning the glottis and the subglottis

Transglottic mass, sagittal line diagram shows a transglottic mass (red color) in the glottis extending into the supraglottis and subglottis

Transglottic mass, coronal line diagram shows the spread of the transglottic cancer in the paraglottic space (PGS)

Large transglottic SCC, axial CT+C shows mass in the supraglottis invading the PES (black asterisk) and right PGS (white asterisk), extra-laryngeal tumor (white arrows) is seen along outer aspect of RT thyroid lamina abutting RT carotid artery (black arrow)

Large transglottic SCC, axial CT shows tumor in RT true cord, anterior commissure (curved black elbow arrow) and anterior LT true cord (thick black arrow), widened thyroarytenoid gap (curved black arrow), extra-laryngeal tumor (thin white arrows) abutting RT carotid artery (black arrow)

Large transglottic SCC, axial CT+C shows subglottic extension with extra-laryngeal tumor (thin white arrows)

Large transglottic SCC, Coronal CT shows the entire extent of transglottic mass spreading along the RT PGS (thin arrows), note the normal LT paraglottic fat space (thick arrow)

Large transglottic SCC, sagittal CT very nicely shows tumor in the lower PES (curved arrow)

c) Staging :-T1 : confined to true vocal cords, normal

mobility-T2 : confined to true vocal cords, limited

mobility but no fixation of cords-T3 : fixation of cords

d) Radiographic Features :1-CT 2-MRI3-PET-CT

1-CT :-Common locations of mass lesions :1-Pyriform sinus (most common)2-Postcricoid3-Posterolateral wall-Determine mobility of cords (fluoroscopy) ,

locate the cause of cord fixation

-Invasion :1-Fat spaces become obliterated, >2 mm soft tissue

indicates tumor spread to contralateral side of cord

2-Thickening of anterior commissure3-Cartilage invasion : erosion, distortion (bowing ,

bulging & buckling) & sclerosis (microinvasion)4-Adenopathy

Axial CT scan shows thickening of the anterior commissure by glottic tumor (arrowhead)

Erosion of the thyroid cartilage (a) and cricoid cartilage (b) indicates cartilage involvement by tumor, sclerosis (arrowhead) is less specific, however may be used as an indicator of cartilage involvement for the arytenoid (c) or cricoid cartilages

Cartilage invasion, (a) CT+C shows LT true cord mass with LT thyroid lamina sclerosis (white arrow) and cricoid destruction (black arrow), (b) axial bone window in another patient shows destroyed LT thyroid lamina and LT cricoarytenoid joint

2-MRI :*T1 : low*T2 : high*T1+C : enhancement*Good for intracartilaginous invasion3-PET-CT :-Has an increasing role play in diagnosis ,

staging and follow-up

Axial T1 demonstrates bulky invasion of the pre-epiglottic space by a supraglottic carcinoma which resulted in invasion of the hyoid bone

Cartilage invasion on MRI, T1+C fat-suppressed shows a large laryngohypopharyngeal mass invading preepiglottic (white asterisk), right paraglottic space (black asterisk) and right piriform sinus (thick arrow), intracartilaginous enhancement is seen of similar intensity as tumor with thin rim of extra-laryngeal tumor (thin arrow)

Cartilage invasion on MRI, (a) T1 shows a large mass destroying the LT thyroid lamina with extra-laryngeal spread encasing LT carotid artery (curved arrow), see the normal ossified RT thyroid lamina (thick arrow), (b) T2 shows the large mass with cartilage destruction , the intracartilaginous signal is similar to the adjacent mass (thin arrow)

6-Postsurgical Larynx :a) Vertical Hemilaryngectomyb) Horizontal Hemilaryngectomy

(Supraglottic) c) Total Laryngectomy d) Radical Neck Dissection

c) Parapharyngeal Space :1-Branchial Cleft Cyst2-Thyroglossal Duct Cyst

1-Branchial Cleft Cyst :a) Incidenceb) Classificationc) Locationd) Radiographic Featurese) Differential Diagnosis

a) Incidence :-Embryologic cysts derived from 1st or 2nd

(most common) cervical pouch-Mass in anterior triangle-May be infected

b) Classification : Bailey and colleagues originally classified four types of BCC

*Type I : is just deep to platysma muscle and the anterior lateral surface of sternocleidomastoid muscle

*Type II : more medial than type I, is seen along the anterior surface of the sternocleidomastoid muscle, just lateral to carotid space and posterior to the submandibular glands, arising on a line between the skin of the lateral neck and the ipsilateral faucial tonsil

*Type III : extend further medially between the internal carotid artery and external carotid artery at the carotid bifurcation, visualization of the cyst’s extension or “tail” between the internal carotid artery and external carotid artery has been considered pathognomonic for type III

*Type IV : is the least common and arises in the pharyngeal mucosal space just deep to the palatine tonsil, often extending upward from tonsil toward the skull base

c) Location :-First branchial cleft anomalies are relatively less

common and typically closely related to the parotid gland (Type I) or appear at the angle of the mandible and may involve the submandibular gland (Type II)

-Typically second branchial cleft cysts present as a rounded swelling just below angle of mandible, anterior to sternocleidomastoid

-Third branchial cleft cyst is characteristically located deep to the sternocleidomastoid muscle

First branchial cleft cyst: (A) Axial and (B) coronal contrast enhanced CT images show a well defined hypodense mass (arrows) within the right parotid gland

Second branchial cleft cyst, CT+C reveals a cystic lesion (arrows) in the right neck lateral to the carotid sheath, behind the submandibular gland and along the anterior border of the sternocleidomastoid muscle

Third branchial cleft cyst, CT+C at the level of the thyroid cartilage reveals a large, well-defined, nonenhancing, water attenuation mass (m) deep to the right sternocleidomastoid muscle (s), medially displacing the common carotid artery and internal jugular vein

d) Radiographic Features :1-U/S2-CT3-MRI

1-U/S :-Sharply demarcated-Posterior acoustic enhancement-Imperceptible walls-Echogenicity is variable :AnechoicHomogeneously hypoechoic with internal

debrisHeterogenous

(a) Longitudinal sonogram of an anechoic second BCC (calipers) with posterior enhancement, (b) Longitudinal sonogram of a second BCC (open arrows), predominantly hypoechoic with faint internal debris. Note the presence of posterior enhancement, (c) Transverse sonogram of a second BCC (straight arrows) with homogeneous, hyperechoic, internal echoes (pseudosolid), note the lack of posterior enhancement, curved arrows identify the bifurcation of the carotid artery, note that no portion of the cyst extends into carotid bifurcation, (d) Transverse sonogram of a second BCC (large arrows) with heterogeneous internal echoes, debris, and septa (small arrows), note the lack of posterior enhancement, curved arrows identify the bifurcation of the carotid artery, note that no portion of the cyst extends into carotid bifurcation, (e) Transverse sonogram of a second BCC (straight arrows) with thick walls (arrowheads) and internal echoes. Note the lack of posterior enhancement, curved arrow identifies the common carotid artery

2-CT :-Rounded, sharply circumscribed-Water density (<20 HU) unless infected

(debris)-Intense rim enhancement in infected cysts-Extension of the cyst wall between the ICA

and ECA just above the carotid bifurcation (sometimes referred to as the notch sign) is said to be pathognomonic

Beak sign (notch sign) in second branchial cleft cyst, CT+C demonstrates a curved rim of hypodense mass (arrows) pointing between left internal and external carotid arteries

3-MRI :*T1 : variable signal dependant on protein

content :High protein content : high signalLow protein content : low signal*T2 : usually high signal*T1+C : no enhancement in uncomplicated

lesions , rim enhancement in infected

Second branchial cleft cyst in a 30-year-old woman with a 14-month history of a mass in the left side of the neck that was unresponsive to antibiotics and that enlarged somewhat the month before surgery, (a) Axial T1 shows a well-defined mass (m) along the anterior border of the left sternocleidomastoid muscle (arrowhead), lateral to the carotid space (white arrow), and posterior to the submandibular gland (black arrow), the classic location for a second branchial cleft cyst, increased signal intensity of the mass is due to either proteinaceous debris or prior hemorrhage, (b) Axial T2 reveals moderate to marked hypointensity of the mass (m), consistent with accumulation of proteinaceous debris or hemorrhage, (c) Coronal T1+C with fat suppression shows mild rim enhancement of the mass (m)

Second Branchial Cleft Cyst, axial non-contrast MRI images (above) T1 and T2 and sagittal T1+C images below, there is a cystic mass filled with a simple fluid surrounded by a homogeneously enhancing thin-wall in the right neck anteriorly, the cyst is located anterior to the right sternocleidomastoid muscle and inferoposterior to the right parotid gland and is most consistent with a second branchial cleft cyst

e) Differential Diagnosis :1-Paramedian thyroglossal cyst2-Cystic lymph nodes :-Necrotic nodal metastases , especially SCC and papillary thyroid

cancer-Tuberculous adenitis3-Vascular lesions :-Jugular vein thrombosis-Mycotic aneurysm of the neck4-Neurogenic tumors :-Schwannoma-Neurofibroma-Ganglioneuroma 5-Cervical dermoid cyst6-Cavernous lymphangioma7-Thyroid nodule/cyst

2-Thyroglossal Duct Cyst :a) Incidenceb) Locationc) Radiographic Featuresd) Differential Diagnosis

a) Incidence :-The most common congenital neck cyst-They are typically located in the midline and are

the most common midline neck mass in young patients

-They typically present during childhood (90% before the age of 10) or remain asymptomatic until they become infected in which case they can present at any time

-The second most common benign neck mass after lymphadenopathy 

b) Location : (Hyoid Bone)-The cysts can occur anywhere along the

course of the thyroglossal duct although infrahyoid location is most common

-Suprahyoid, 20%-At hyoid bone, 15%-Infrahyoid, 65%

Thyroglossal duct diagram

Normal adult neck, sagittal CT+C shows the normal anatomic course of the thyroglossal duct (magenta line), the thyroid primordium originates as the median thyroid anlage (•) at the foramen cecum (white arrow), the path of the primordial descent wraps anteriorly, inferiorly, and posteriorly to the hyoid bone (black arrow) and courses anteriorly to the thyrohyoid membrane and thyroid cartilage (arrowhead)

c) Radiographic Features :1-U/S2-CT3-MRI

1-U/S :-As branchial cleft cyst

2-CT & 3-MRI :-As branchial cleft cyst-Anterior midline or para-midline location

(a) Longitudinal sonogram of a predominantly anechoic TDC with internal debris and thick walls (solid white arrows) below the level of the hyoid bone (black arrow), open arrow indicates the head end of the patient, (b) Longitudinal sonogram of an anechoic, multiloculated TDC (solid white arrows) with extension posterior to the hyoid bone (black arrow), open arrow indicates the head end of the patient

(a) Transverse sonogram of a uniformly echogenic, pseudosolid appearance of a TDC (large arrows), note, however, the posterior enhancement (small arrows), suggesting its cystic nature, (b) Longitudinal sonogram of a TDC shows a mixed echo pattern with internal debris (arrowhead) and septa (solid arrows). Note its relationship to the hyoid bone (H) and the intense posterior enhancement, open arrowindicates the head end of the patient

Longitudinal sonogram of a TDC shows thick septa (solid arrows), note its relationship to the hyoid bone (H) and the intense posterior enhancement, open arrow indicates the head end of the patient

Thyroid ectopia associated with the hyoid bone in three patients, (a) Axial CT+C of a 36-year-old man shows a thyroglossal duct cyst (arrowhead) intimately involved with the anterior aspect of the hyoid bone (black arrow); normal fat is preserved in the preepiglottic space (white arrow), (b, c) Sagittal (b) and axial (c) CT+C of a 49-year-old man depict a thyroglossal duct cyst that conforms to the embryologic course of the thyroglossal duct (magenta line in b), both anterior and posterior to the hyoid bone, and compresses the preepiglottic fat (arrow), (d) Axial CT+C image of a 28-year-old woman shows ectopic thyroid tissue in the same position as in c, appearing both anterior and posterior to the hyoid bone

Paramedian thyroglossal duct cyst

Paramedian thyroglossal duct cyst

T2 fat satturated

d) Differential Diagnosis : Midline neck masses1-Lymph Nodes :-Inflammatory adenopathy-Malignant2-Thyroid Gland : (7)-Thyroglossal duct cyst-Thyroid cyst-Thyroid neoplasm-Multinodular goiter-Thyroiditis-Ectopic thyroid-Parathyroid adenoma

3-Larynx :-Laryngocele4-Ranula (sublingual gland)5-Epidermoid Cyst6-Neurofibroma7-Cystic Hygroma / Lymphangioma :-Well circumscribed and are of fluid density-90 % in children < 2 years-Mostly located in the posterior cervical space-High signal on T2 , variable signal on T1 (depend on protein

content) 8-Hemangioma / Vascular malformation9-Lipoma

*N.B. : Neck masses in infants & childrena) Soft :1-Lipoma2-Vascular malforamtion3-Lymphatic malforamtionb) Firm :1-Cyst : thyroglossal , branchial cleft , lingual and thymic2-Abscess3-Hematoma4-Lymphadenopathy5-Fibromatosis coli6-Rhabdomyosarcoma7-Thyroid :-Diffuse enlargement (Grave’s disease , MNG & Thyroiditis)-Focal mass (Cyst , benign adenoma , malignancy is rare ,

papillary carcinoma being the most common malignancy)