Endo - diagnostic tests quiz

Question 1

Investigation for Cushing’s

Answer 1

1mg Dexamethasone suppression test or urinary cortisol or midnight salivary cortisol

Question 2

Cause of a positive dexamethasone suppression test

Answer 2

Cushing’s disease

Question 3

Pathology of Cushing’s

Answer 3

Excess ACTH from pituitary adenoma

Question 4

Investigation for Pheochromocytoma

Answer 4

Plasma free metanephrines

Question 5

Cause of elevated plasma free metanephrines

Answer 5

Phaeochromocytoma

Question 6

Pathophysiology of Phaeochromocytoma

Answer 6

Excess Catecholamines secreted by adrenal tumour

Question 7

Investigation for Conn’s disease

Answer 7

Aldosterone-Renin-Ratio

Question 8

Cause of elevated aldosterone-renin-ratio

Answer 8

Conn’s disease

Question 9

Pathology of Conn’s disease

Answer 9

Excess aldosterone secreted by hyper-functioning adrenal glands or adrenal tumour

Question 10

Investigation for Addison’s

Answer 10

Short Synacthen test -> high ACTH, elevated plasma renin

Low early morning serum cortisol is suggestive (but not diagnostic), also expect low urinary cortisol (non-diagnostic)

Question 11

Cause of positive short synacthen test

Answer 11

Addison’s

Question 12

Pathology of Addison’s

Answer 12

Adrenal: glucocorticoid and mineralocorticoid insufficiency

Question 13

Investigation for Acromegaly

Answer 13

IGF-1

Question 14

Pathology of Acromegaly

Answer 14

Excess GH