Chapter 21: Endocrine Pituitary Adenomas Flashcards
The most common mutation in sporadic pituitary adenoma is…
Activating mutation to the GSP gene -> excess adenylate cyclase activity -> hypersecretion.
What cancers are common in the MEN1 syndrome?
Pituitary adenoma Parathyroid Pancreatic islet cell Due to Menin tumor suppressor mutation.
What tumors are included in the Carney Complex?
Pituitary Adenoma Myxomas Pigmentation Endocrine hyperactivity PKA-regulatory subunit 1a -> GH and prolactin secretion -> Acromegaly
What is charactersitic of FIPA?
Familial isolated pituitary adenomas. Younger patient Mutation of AIP (aryl-hydroacrbon receptor interacting protein) Aggressive tumor
What is a microadenoma?
<10mm, symptomatic if secrete hormone
What is a macroadenoma? Complications?
>10mm, compression or hormone secretion. Impinge optic chiasm -> Bi-temporal hemianopsia and headache Oculomotor nerve palsies Invasion of hypothalamus -> Temp dysregulation and hyperphagia
The msot common hormone secreting tumor in adults and children is…
Prolactinoma
In the elderly, consider this pituitary adenoma…
GnRH adenoma.
Patient presents with amenorrhea, galactorrhea, infertility, breast tenderness and enlargement.
Male patient presents with decreased libido and impotence.
Prolactinoma
Histology: Chromophobic, spheroid nuclei with prominent nucleoli, amyloid deposits and psammoma bodies, immunostain for PRL reveals “golgi pattern”.
Treat a prolactinoma with…
A dopamine agonist (bromocriptine)
Patient presents with headache, visual changes, and acromegaly.
Histology shows this:
Growth hormone adenoma (somatotropic cell adenoma).
Patient presents with acromegaly and sexual dysfunction (libido, erection).
Two cell types are found to compose the tumor.
Mixed somatotrope + lactotroph adenoma. Prolactinoma with GH adenoma.
Patient presents with acromegaly and sexual dysfunction (libido, erection).
One cell type composes the tumor.
Mammosomatotrope adenoma
A pituitary adenoma with monomorphic cells with nuclear pleomorphism, giant mitochondria, vacuoles, and keratin 8+. Clinically aggressive
Acidophile stem cell adenoma.
Patient presents with moon facies, a buffalo hump, central obesity, and hirsutism. A pituitary tumor is discovered.
Corticotrope adenoma -> Cushing disease.
PAS+, basophilic (chromophobic more aggressive
ACTH-secreting pituitary tumor with filaments visable by light microscopy.
Crooke hyalinization, made of Type I intermediate filaments.
Patient presents with headache and visual disturbance. A pituitary tumor is found and a biopsy is performed.
The tumor has pseudorosettes and pseudopapillae, chromophobic, PAS negative.
Tumor cells are immunofluorescent for beta-FSH, beta-LH, and alpha glycoprotein.
Gonadotrope adenoma.
Patient presents with a pituitary mass and goiter.
TSH-producing adenoma.
Histology: Polyhedral or columnar cells with pseudorosettes around blood vessels.
A non-hormonal pituitary adenoma that is chromophobic, PAS negative, may show pseudopapillary growth.
No hormone staining - may stain for chromogranin A and synaptophysin.
Null cell adenoma.
A non-hormonal pituitary adenoma that has enlarged granular eosinophilic cells that are packed with mitochondria.
Oncocytoma
A non-hormonal pituitary adenoma that is well-differentiated and is often positive for ACTH or GH, but is not secretory.
Silent adenoma.
Patient presents with polyuria and polydipsia.
On administration of synthetic vasopressin, patient is able to concentrate urine.
Central diabetes insipidus. Loss of ADH (vasopressin) secretion from posterior pituitary/neurohypophysis. Trauma, surgery, craniopharyngioma (adamantinomatous/catenin gene or papillary).
Diabetes insipidus caused by loss of ADH effect.
Nephrogenic DI, vasopressin V2 receptor problem.
Diabetes insipidus caused by inappropriate thirst.
Dipsogenic DI, damage to brain.
Diabetes insipidus due to enzymatic degradation of ADH.
Gestational DI, placental vasopressin-ases.
Patient presents with water retention, hyponatremia, seizures, coma, possibly death.
Small cell lung carcinoma is discovered.
Syndrome of inapproprate ADH (SIADH).
