Clinical chemistry

Question 1

Low ACTH. Low and high dose DEXA had no effect

Answer 1

Primary hypercorticolism

Question 2

Somewhat elevated ACTH. Low dose DEXA has no effect, but high dose results in suppression.

Answer 2

Secondary hypercorticolism (Cushing’s disease). Pituitary still has some -ve feedback.

Question 3

High ACTH. Low and high dose DEXA have no effect.

Answer 3

ectopic ACTH secretion