Chapter 21: Endocrine Pituitary Adenomas

Question 1

The most common mutation in sporadic pituitary adenoma is…

Answer 1

Activating mutation to the GSP gene -> excess adenylate cyclase activity -> hypersecretion.

Question 2

What cancers are common in the MEN1 syndrome?

Answer 2

Pituitary adenoma Parathyroid Pancreatic islet cell Due to Menin tumor suppressor mutation.

Question 3

What tumors are included in the Carney Complex?

Answer 3

Pituitary Adenoma Myxomas Pigmentation Endocrine hyperactivity PKA-regulatory subunit 1a -> GH and prolactin secretion -> Acromegaly

Question 4

What is charactersitic of FIPA?

Answer 4

Familial isolated pituitary adenomas. Younger patient Mutation of AIP (aryl-hydroacrbon receptor interacting protein) Aggressive tumor

Question 5

What is a microadenoma?

Answer 5

<10mm, symptomatic if secrete hormone

Question 6

What is a macroadenoma? Complications?

Answer 6

>10mm, compression or hormone secretion. Impinge optic chiasm -> Bi-temporal hemianopsia and headache Oculomotor nerve palsies Invasion of hypothalamus -> Temp dysregulation and hyperphagia

Question 7

The msot common hormone secreting tumor in adults and children is…

Answer 7

Prolactinoma

Question 8

In the elderly, consider this pituitary adenoma…

Answer 8

GnRH adenoma.

Question 9

Patient presents with amenorrhea, galactorrhea, infertility, breast tenderness and enlargement.

Male patient presents with decreased libido and impotence.

Answer 9

Prolactinoma

Histology: Chromophobic, spheroid nuclei with prominent nucleoli, amyloid deposits and psammoma bodies, immunostain for PRL reveals “golgi pattern”.

Question 10

Treat a prolactinoma with…

Answer 10

A dopamine agonist (bromocriptine)

Question 11

Patient presents with headache, visual changes, and acromegaly.

Histology shows this:

Answer 11

Growth hormone adenoma (somatotropic cell adenoma).

Question 12

Patient presents with acromegaly and sexual dysfunction (libido, erection).

Two cell types are found to compose the tumor.

Answer 12

Mixed somatotrope + lactotroph adenoma. Prolactinoma with GH adenoma.

Question 13

Patient presents with acromegaly and sexual dysfunction (libido, erection).

One cell type composes the tumor.

Answer 13

Mammosomatotrope adenoma

Question 14

A pituitary adenoma with monomorphic cells with nuclear pleomorphism, giant mitochondria, vacuoles, and keratin 8+. Clinically aggressive

Answer 14

Acidophile stem cell adenoma.

Question 15

Patient presents with moon facies, a buffalo hump, central obesity, and hirsutism. A pituitary tumor is discovered.

Answer 15

Corticotrope adenoma -> Cushing disease.

PAS+, basophilic (chromophobic more aggressive

Question 16

ACTH-secreting pituitary tumor with filaments visable by light microscopy.

Answer 16

Crooke hyalinization, made of Type I intermediate filaments.

Question 17

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.

Answer 17

Gonadotrope adenoma.

Question 18

Patient presents with a pituitary mass and goiter.

Answer 18

TSH-producing adenoma.

Histology: Polyhedral or columnar cells with pseudorosettes around blood vessels.

Question 19

A non-hormonal pituitary adenoma that is chromophobic, PAS negative, may show pseudopapillary growth.

No hormone staining - may stain for chromogranin A and synaptophysin.

Answer 19

Null cell adenoma.

Question 20

A non-hormonal pituitary adenoma that has enlarged granular eosinophilic cells that are packed with mitochondria.

Answer 20

Oncocytoma

Question 21

A non-hormonal pituitary adenoma that is well-differentiated and is often positive for ACTH or GH, but is not secretory.

Answer 21

Silent adenoma.

Question 22

Patient presents with polyuria and polydipsia.

On administration of synthetic vasopressin, patient is able to concentrate urine.

Answer 22

Central diabetes insipidus. Loss of ADH (vasopressin) secretion from posterior pituitary/neurohypophysis. Trauma, surgery, craniopharyngioma (adamantinomatous/catenin gene or papillary).

Question 23

Diabetes insipidus caused by loss of ADH effect.

Answer 23

Nephrogenic DI, vasopressin V2 receptor problem.

Question 24

Diabetes insipidus caused by inappropriate thirst.

Answer 24

Dipsogenic DI, damage to brain.

Question 25

Diabetes insipidus due to enzymatic degradation of ADH.

Answer 25

Gestational DI, placental vasopressin-ases.

Question 26

Patient presents with water retention, hyponatremia, seizures, coma, possibly death.

Small cell lung carcinoma is discovered.

Answer 26

Syndrome of inapproprate ADH (SIADH).