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