Pituitary Adenoma Abdulaziz R. Alanzi Medical Student, Al-Imam University Riyadh, Saudi Arabia

Overview

Pituitary adenoma is primary tumor that occur in the pituitary gland.

99% of pituitary gland tumors are benign

Most commonly diagnosed in people between the ages of 30 and 50 years

Accounts for 10-15% of all intracranial tumors.

Symptomatic prolactinomas and Cushing disease are found more frequently in women.

Pituitary adenomas are classified by their cell of origin

(lactotroph, gonadotroph, somatotroph, corticotroph, and thyrotroph)

and their size: microadenoma (diameter < 1cm),

macroadenoma (diameter ≥ 1cm)

Risk Factors

Multiple endocrine

neoplasia (MEN) type 1

Pituitary Adenoma

Parathyroid Tumor

Pancreatic Tumor

Carney complex

Pituitary Adenoma

Adrenal Tumors

Myxomas

Familial isolated pituitary adenoma

McCune-Albright syndrome Acromegaly

Prolactinoma Growth Hormone Secreting Tumor

1

2

3

4

Clinical Manifestations

Mass effect: Headache Visual Defects:

Bitemporal hemianopia(due to compression of optic chiasm).

Clinical ManifestationsHormonal deficiencies - Clinical effects

Growth hormone deficiency

• Adults - Increased rate of cardiovascular disease, obesity, reduced muscle strength and exercise capacity, and increased cholesterol

• Infants –Hypoglycemia

• Children - Decreased height and growth rate

Gonadotrophin deficiency

• Men - Diminished libido and impotence; testes shrink in size, but spermatogenesis generally preserved

• Women - Diminished libido and dyspareunia; breast atrophy in chronic deficiency

• Children - Delayed or frank absence of puberty

Thyrotropin deficiency

• Malaise, • weight gain, • lack of energy, • cold intolerance, • constipation

Clinical ManifestationsHormonal deficiencies - Clinical effects

Corticotrophin deficiency

• Initially, symptoms nonspecific (eg, weight loss, lack of energy, malaise); severe adrenal insufficiency may present as a medical emergency

Panhypopituitarism

Refers to deficiency of

several anterior pituitary

hormones.

Clinical ManifestationsHormonal overproduction - Clinical effects

Prolactin *

• Hypogonadism, if hyperprolactinemia sustained

• Women - Amenorrhea, galactorrhea, and infertility

• Men - Decreased libido, impotence, and rarely galactorrhea

Growth hormone

• Children and adolescents - May result in pituitary gigantism

• Adults – Acromegaly Changes in the size of the hand and feet, coarseness of the face, frontal bossing, and prognathism result. Further changes in the voice, and hirsutism, confirm the diagnosis.

• Acromegaly frequently results in glucose intolerance, with 20% of patients progressing to diabetes mellitus.

• Carpal tunnel syndrome is seen frequently.

Cushing disease

• Weight gain, central obesity, moon facies, violet striae, easy bruisability.

Clinical Examination Finding

Visual acuity can be decreased in one or both eyes.

Pupillary light reaction can be abnormal.

Color vision can be affected.

Larger lesions may be associated with a bitemporal hemianopsia.

Optic atrophy is seen frequently

Neuro-ophthalmologic examination

Clinical Examination Finding

Prolactinomas

In females, galactorrhea may be present on clinical examination. Women undergoing an infertility evaluation may be found to have a prolactinoma.

In males, galactorrhea is infrequent; testicles may be decreased in size and may be soft to palpation.

Chronic hypopituitarism results in hypotension, generalized weakness, hypothermia, malaise, and depression.

Acute sudden hypopituitarism (ie, pituitary apoplexy) is associated with shock, coma, and death.

Hypopituitarism

Clinical Examination Finding

Cushing Disease

Findings are prominent and include obesity, centripetal fat deposition, proximal myopathy, moon facies, buffalo hump, posterior subcapsular cataracts, arterial hypertension, bruises, and skin striae.

Clinical Examination Finding

Large hands and feet (with thick fingers and toes) and coarse facial features with frontal bossing. Women may appear masculinized. Other findings might include prognathism, carpal tunnel syndrome, and voice quality changes.

Acromegaly

Differential Diagnosis

Craniopharyngioma

Rathke's cleft cyst

Meningioma

Brainstem Gliomas

Glioblastoma Multiforme

Germinoma

Pituitary hyperplasia

Ependymoma

Low-Grade Astrocytoma

Primary CNS Lymphoma

Diagnosis

Blood chemistry tests: pituitary hormones level:

Prolactinomas: Serum prolactin level

Growth hormone abnormalities: Growth hormone (GH) levels - insulin-like growth factor-1 (IGF-1) - Oral glucose tolerance test

Cushing disease: 24 hrs urine collection for free cortisol, Dexamethasone suppression test, Serum levels of ACTH.

Thyroid hormones, including thyrotropin (TSH), thyroxine (T4) and triiodothyronine (T3)

Luteinizing hormone (LH) - follicle-stimulating hormone (FSH) - estrogen - estradiol - testosterone

Imaging Tests: MRI, CT-Scan

Staging

0 Pituitary gland appears normal.

I Microadenoma enclosed within the sella turcica.

II Macroadenoma enclosed within the sella turcica.

III Tumour invades into the sella turcica locally (in one place).

IV Tumour invades into the sella turcica diffusely (in more than one place).

Classification for pituitary adenomas based on imaging

A 0–10 mm suprasellar extension occupying the suprasellar cistern

B 10–20 mm extension and elevation of the third ventricle

C 20–30 mm extension occupying the anterior (front) of the third ventricle

DLarger than 30 mm extension, beyond the foramen of Monro, or grade C with lateral extensions

Grading for suprasellar extension

Management - Hormonal deficiencies

Management - Hormonal overproduction

Prolactinoma:

Dopaminergic agonists (bromocriptine, cabergoline and Quinagolide)

Growth hormone-secreting tumors:Gonadotropin-secreting pituitary tumor:Thyrotropin-secreting tumors

• Surgery, often followed by radiation therapy.

• Medical treatment (Octreotide)

Nonsecretory pituitary adenomas 

• Surgery• If surgery is contraindicated, medical treatment (Bromocriptine or Octreotide)

Management - Hormonal overproduction

Corticotropin-secreting pituitary tumors:

• surgery and radiation therapy # Medical therapy:• Central acting agents: (bromocriptine, valproic acid, and cyproheptadine).

• Peripheral acting agents: (ketoconazole, mitotane, and metyrapone).

Complications

Vision loss

Pituitary hormone insufficiency, including diabetes insipidus, hypothyroidism, and hypogonadism, may occur.

Pituitary apoplexy: is bleeding into or impaired blood supply of the pituitary gland at the base of the brain.

Summary

99% of pituitary gland tumors are benign

Accounts for 10-15% of all intracranial tumors.

Risk factors include MEN type 1, Carney complex, Familial isolated pituitary adenoma…etc

Clinical manifestation include headache, visual defects, and other symptoms depending on which pituitary hormone involved in the disease.

The diagnosis is confirmed by testing hormone levels, and by radiographic imaging of the pituitary.

Management include surgery, radiation therapy, medical therapy depending of the type of pituitary adenoma.

Complications might include vision loss, pituitary hormone insufficiency, pituitary apoplexy.

References

Thank You

.AbdulazizROA@gmail com

@Azizocyte