Pituitary disease

Question 1

Pituitary adenoma can be classified by

Answer 1

Size - <1cm microadenoma or >1cm macroadenoma

Hormonal status - secretory or non-secretory adenoma

Question 2

Most common type of adenoma

Answer 2

1) Prolactinoma (50%)

2) non-secreting
3) GH secreting
4) ACTH secreting

Question 3

Pituitary adenomas cause symptoms by (4):

Answer 3

1) Excess of a hormone
2) Depletion of a hormone (compression of the functioning PG)
3) Stretching of the dura around pituitary fossa (headaches)
4) Compression of optic chiasm (bitemporal/heteronymous hemianopia)

Question 4

Pituitary adenoma that produces excess ACTH causes..

Answer 4

Cushing’s disease

Question 5

Pituitary adenoma that produces excess GH causes..

Answer 5

Acromegaly

Question 6

Investigations for pituitary adenoma

Answer 6

1) Pituitary blood profile- GH, prolactin, ACTH, FH, LSH and TFTs
2) Visual field test (heteronymous hemianopia seen)
3) MRI with contrast

Question 7

Treatment for pituitary adenoma

Answer 7

Hormonal therapy (bromocriptine for prolactinomas)
Surgery
Radiotherapy

Question 8

What is the main prolactin inhibitory factor (NT) ?

Answer 8

Dopamine

Question 9

What can be used to treat symptoms of a prolactinoma

Answer 9

Bromocriptine (Dopamine agonist)

Question 10

Features of excess prolactin in men

Answer 10

Impotence, loss of libido, galactorrhoea, gynaecomastia

Question 11

When are prolactinomas commonly diagnosed?

Answer 11

During investigation of secondary amenorrhoea or galactorrhoea

Question 12

Causes of raised prolactin

Answer 12

pregnancy
prolactinoma
physiological
PCOS
Primary hypothyroidism (due to TRH stimulating prolactin release)
phenothiazines, metoclopramide, domperidone

Question 13

Drugs that raise prolactin levels

Answer 13

Mainly dopamine antagonists (note: dopamine usually inhibits prolactin release)

Anti-emetics- metoclopramide, domperidone
Anti-psychotics - haloperidol, prochlorperaine, chlorpromazine

Question 14

Hypothalamus hormones (7)

Answer 14

TRH
CRH
GHRH
GnRH

Oxytocin
Vasopressin
Somatostatin (GHIH)

Question 15

PG hormones (8)

Answer 15

TSH 
ACTH 
GH 
FSH 
LH 
Prolactin 

Oxytocin
Vasopressin (ADH)

Question 16

Main cause of acromegaly

Answer 16

Pituitary adenoma

Ectopic tumours producing excess GHRH/GH

Question 17

Acromegaly features (overgrowth of tissues and space occupying lesion)

Answer 17

Coarse facial appearance (Frontal bossing, large nose, macroglossia)
Protruding jaw
Spade hands and large feet

Compression of optic chiasm by PG (Bitemporal hemianopia an headaches)

Question 18

Treatment of acromegaly

Answer 18

FIRST LINE = trans-sphenoidal surgery (remove PG tumour or ectopic tumour)

Medication - Pegvisomant (GH antagonist) given subcut daily

Ocreotide (Somatostatin analogues)

Bromocriptine (Dopamine agonist)

Question 19

Somatostatin/GHIH- where is it released and what does it do?

Answer 19

Released from hypoT, GI tract and pancreas

Inhibits release of GH from PG

Question 20

Complications of acromegaly

Answer 20

Cardiomyopathy (hypertrophy)
HTN
T2D
Colorectal cancer

Question 21

SIADH =

Answer 21

Syndrome of inappropriate ADH secretion

Characterised by hyponatraemia secondary to the dilutional effects of excessive water retention

Question 22

Drugs that cause SIADH

Answer 22

sulfonylureas*
SSRIs, tricyclics (fluoxetine, amytriptyline) 
carbamazepine
vincristine
cyclophosphamide

Question 23

SIADH is seen in which type of malignancy

Answer 23

Small cell lung cancer