Pituitary

Question 1

Which organ does growth hormone work on and what is produced?

Answer 1

GH works on the liver - produces IGF -1 and IGF - 2

Question 2

What is released from the hypothalamus to stimulate ACTH production?

Answer 2

CRH

Question 3

What is released from the hypothalamus to stimulate TSH production?

Answer 3

TRH

Question 4

What are the two receptors on which vasopressin works?

Answer 4

V1 - vasoconstriction
V2 - water reabsorption

Question 5

What is pituitary apoplexy?

Answer 5

Ischemia - sudden onset - due to a tumour

Question 6

Explain the pathophysiology of Sheehan’s syndrome

Answer 6

Lactotrophs become larger in pregnancy, so more blood supply is required, hence when there is blood loss during pregnancy, there is a risk of ischemia.

Question 7

List three causes of hypopituitarism

Answer 7

Infection - meningitis TB
Inflammation - sarcoidosis
Adenomas - functioning/non-functioning
Craniopharyngiomas
Vascular - Sheehan’s syndrome
Iatrogenic - surgery/radiation

Question 8

What is the function of oxytocin?

Answer 8

Lactation and uterine contraction in pregnancy

Question 9

What is the most common type of pituitary adenoma?

Answer 9

Prolactinoma over 6000

Then non-functioning macroadenoma

Question 10

What is the difference between a non-functioning macroadenoma vs prolactinoma?

Answer 10

If the prolactin is over 6000, it’s likely a prolactinoma

However NFMA can also lead to compression of the pituitary stalk, leading to a prevention of the dopamine getting to the anterior pituitary.

Question 11

Symptoms of prolactinoma

Answer 11

Galactorrhoea
Amenorrhea
Bitemporal hemianopia

Question 12

Combined pituitary function test

Answer 12

Anterior pituitary - GH, ACTH, Prolactin, TSH/FSH

Question 13

How do we measure hypopituitarism

Answer 13

Insulin - causes stress - so causes GH release and cortisol release

TRH - stimulates TSH and prolactin

GnRH - LH/FSH

Answer 14

Glucose target above 2.2mM

Question 15

Cortisol above 400?

Question 16

Woman presents with a headache and bitemporal hemianopia, pituitary adenoma = 4mm. Prolactin = 1400 IU/L. Cause?

Answer 16

Can’t be a macroadenoma
Can’t be a

Question 17

Prolactinoma management

Answer 17

Cabergoline - D2 agonist

Question 18

How do you manage

Answer 18

Corticosteroids - replace FIRST
Thyroxine
GH
Oestrogen/prog/testosterone

Question 19

Signs and symptoms of acromegaly

Answer 19

Headaches
Hyperhidrosis

Spade-like hands
Prominent supraorbital ridges
Increased interdental spaces
Macroglossia
Prognathism
Bitemporal hemianopia

Question 20

Investigation for acromegaly

Answer 20

Oral glucose tolerance test - normally growth hormone should reduce if you give them glucose. But in acromegaly you get a paradoxical rise.

Question 21

Management

Answer 21

Transphenoidal surgery
D2 receptor agnosits - cabergoline/ocreotide

Question 22

What do you call the erythematous nodules on the shins of someone with sarcoidosis?

Question 23

Enzyme that causes hypercalcemia in sarcoidosis + where are they found?

Answer 23

ectopic 1 alpha hydroxylase from non-caseating granulomas