Pitutary

Question 1

Commonest cause of death in acromegaly

Answer 1

CHF

Question 2

Best initial/ screening test for acromegaly

Answer 2

IGF-1

GH level measurement is not the answer because of its diurnal variation (highest at night)

Question 3

What’s metyrapone stimulation test?

Answer 3

It inhibits 11-beta hydroxylase-> low cortisol production-> rise in ACTH level would be the normal response but in hypopituitarism, no rise in ACTH is seen

Question 4

Central Vs nephrogenic diabetes insipidus- serum Na level

Answer 4

Central usually >150

Nephrogenic -142-150

Question 5

First n second line Rx for prolactinoma; symptomatic Vs Asymptomatic, size

Answer 5

Asymptomatic microadenoma (<10mm) doesn’t need Rx

• symptomatic or tumor size>1cm 1st line dopamine agonists- preferably cabergoline which is better tolerated than bromocriptine
• second line- trans sphenoidal surgery- if they don’t respond to drugs or if tumor size >3cm

Question 6

Increased hat size, carpal tunnel syndrome, coarsening facial features; sweat gland hypertrophy
Dx?

Answer 6

Acromegaly

Question 7

The most sensitive dynamic test for acromegaly

Answer 7

75 g oral glucose suppression test-> GH level will b suppressed to < 1mg/dl

Question 8

Prolactin level elevation in non functioning pituitary adenoma is due to?

Answer 8

Anatomic disruption of the dopaminergic neural pathway that normally suppresses prolactin secretion

Question 9

An adult male came with a recent onset gynecomastia and low LH n FSH levels and a Dx of a non-pituitary tumor is made. What’s it?

Answer 9

Leydig cell tumor (a sex cord tumor). Leydig cells r the principal sources of testosterone and r capable of producing estrogen due to markedly increased aromatase expression

Question 10

Panhypopituitarism- hyponatremia or hypernatremia? Why?

Answer 10

Hyponatremia; due to inappropriate increase in ADH level or low cortisol

Question 11

Hypopituitarism with mild to moderate increase in prolactin suggests?

Answer 11

Non-functioning (gonadotroph) adenoma, I.e, the most common form of non functioning pituitary adenoma arises from gonadotrophs.

Question 12

Fatigue, loss of appetite, hypoglycemia, hyponatremia, low libido, erectile dysfunction, cold intolerance, bradycardia, progressive headache… r sxs of?

Answer 12

Panhypopituitarism

Question 13

Primary polydipsia Vs DI

• urine osmolality
• serum Na

Answer 13

PP- dilute urine; hyponatremia ( serum Na<137)

DI- dilute urine; serum Na>145

Question 14

The most common primary pituitary tumor arises from which cells?

Answer 14

Lactotrophs/prolactinoma