Endocrine surgery- pituitary, adrenal and MEN

Question 1

Hormones secreted by the anterior pituitary and their “controlling” hypothalamic hormones? (6)

Answer 1

Growth hormone (growth hormone-releasing hormone)
Prolactin (prolactin-inhibiting factor, i.e. dopamine)
Adrenocorticotropic hormone (corticotrophin-releasing ormone)
Lutenizing hormone (GnRH)
Follicle stimulating hormone (GnRH)
Thyroid stimulating hormone (Thyroid releasing hormone)

Question 2

How does the hypothalamus communicate with the anterior pituitary?

Answer 2

Portal venous system which runs down the hypothalamic stalk

Question 3

How would the secretion of anterior pituitary hormones be affected by the complete division of the hypothalamic stalk?

Answer 3

Secretion of all hormones would be suppressed, except prolactin which would increase

Question 4

Imaging modalities for suspected pituitary adenomas?

Answer 4

Contrast-enhanced CT or MRI

Question 5

Features of acromegaly? (6)

Answer 5

Large extremities
Coarsened facial expression
Increased sweating and acne
Headache
Visual field defects (usually bitemporal hemianopia)
Carpal tunnel syndrome

Question 6

Diagnostic test for acromegaly?

Answer 6

IGF-1 levels

Glucose tolerance test (glucose should suppress IGF-1)

Question 7

Why is IGF-1 used as test for acromegaly rather than GH?

Answer 7

IGF-1 is more stable with a longer half-life; GH secretion is episodic

Question 8

Treatment of acromegaly? (4)

Answer 8

Trans-sphenoidal removal of adenoma

Drug treatment:
somatostatin analogues (e.g. octreotide)
bromocriptine (dopamine agonist)
pegmivosant ( modified GH analogue- acts as an antagonist at GH receptors)

Question 9

Features of hyperprolactinaemia in a) males b) females

Answer 9

a) impotence and gynaecomastia

b) galactorrhoea and amenorrhoea

Question 10

Three main clinical syndromes that result from an anterior pituitary adenoma?

Answer 10

Acromegaly
Hyperprolactinaemia
Cushing’s disease (excess ACTH secretion)

Question 11

Structure of the adrenal gland and its secretions?

Answer 11

Outer cortex:
zona glomerulosa- aldosterone
zona fasciculata and zona reticularis- cortisol, androgens, oestrogens

Inner medulla-adrenaline, noradrenaline and dopamine

Question 12

Control of

a) cortisol
b) aldosterone secretion?

Answer 12

a) pituitary ACTH

b) mainly by angiotensin II (as a result of renin release from the renal JGA)

Question 13

Causes of Cushing syndrome? (4)

Answer 13

Adrenal cortex tumours (usually an adenoma)
Pituitary tumours
Ectopic ACTH secretion
Iatrogenic due to administration of exogenous steroids

Question 14

Clinical features of Cushing syndrome? (7)

Answer 14

Truncal obesity
Buffalo hump
Livid striae
Proximal muscle weakness
Osteoporosis
Diabetes
Hypertension

Question 15

Diagnostic tests for Cushing’s syndrome?

Answer 15

24-hour urinary free cortisol

Dexamethasone suppression test

Question 16

What investigation helps distinguish between adrenal and pituitary causes of Cushing’s?

Answer 16

ACTH

also imaging- MRI pituitary, CT chest and abdomen

Question 17

Treatment of an adrenal cortex tumour?

Answer 17

Unilateral adrenalectomy, with steroid replacement until the suppressed contralateral adrenal tumour recovers function

Question 18

How is pituitary Cushing’s managed?

Answer 18

Removal of the adenoma

Question 19

What is Conn’s syndrome? What are the causes?

Answer 19

Primary hyperaldosteronism due to an adrenal adenoma

Question 20

Clinical features of hyperaldosteronism?

Answer 20

Hypertension, headache, visual disturbance, hypokalaemia

Question 21

Primary and secondary causes of hyperaldosteronism?

Answer 21

Primary- Conn’s syndrome (adenoma) and bilateral adrenal hyperplasia
Secondary- due to excess renin secretion

Question 22

Investigations used in hyperaldosteronism?

Answer 22

Renin and aldosterone levels (renin undetectable in primary)
Plasma/urine aldosterone
Selective adrenal vein sampling/imaging to confirm adenoma
U&Es

Question 23

What accounts for 80% of phaeochromocytoma? What accounts for the rest?

Answer 23

Tumours of the adrenal medulla

Extra-adrenal tumours

Question 24

Clinical features of phaeochromocytoma?

Answer 24

Paroxysmal hypertension
Tachycardia, palpitations
Hypertension
Thyrotoxicosis
Diabetes mellitus

Question 25

What proportion of phaeochromocytoma are a) malignant and b) multiple?

Answer 25

a) 10%

b) 10%

Question 26

Investigation of suspected phaeochromocytoma?

Answer 26

24-hour urinary catecholamines

CT/MRI of the abdomen, MIBG scintigraphy

Question 27

Pre-surgical management of phaeochromocytoma?

Answer 27

Alpha blockade and beta blockade

Question 28

Variably penetrant autosomal dominant trait associated with hyperplasia/adenoma of the parathyroid, pancreatic islets and anterior pituitary?

Answer 28

MEN type I

Question 29

Variably penetrant autosomal dominant trait associated with medullary thyroid cancer, phaeochromocytoma and parathyroid hyperplasia?

Answer 29

MEN type II

Question 30

Proto-oncogene implicated in MEN Type II?

Answer 30

Ret

Question 31

Diffuse haemorrhage of the adrenal glands?

Answer 31

Waterhouse-Friderichsen syndrome

Question 32

Well-circumscribed adrenal nodule with lipid-rich core?

Answer 32

Benign incidental adenoma