Which disorder causes the adrenal cortex to secrete too much cortisol?

Which disorder causes the adrenal cortex to secrete too much cortisol?

• A. Cushing disease
• B. Cushing syndrome
• C. Addison disease
• D. Pheochromocytoma

Answer: (A)

Excess cortisol that originates from stimulation of the adrenal cortex by ACTH is at the heart of this question. In Cushing disease, a pituitary adenoma makes too much ACTH, which drives the adrenal cortex to produce and release more cortisol than normal. That direct pituitary source of ACTH leading to adrenal cortisol overproduction is why Cushing disease is the best answer for a pituitary-driven cause of hypercortisolism. It's worth noting that Cushing syndrome is the broader term for high cortisol levels from any cause—pituitary (Cushing disease), ectopic ACTH, adrenal tumors, or external steroid use. Addison disease is the opposite process (adrenal insufficiency, low cortisol). Pheochromocytoma involves excess catecholamines from the adrenal medulla, not cortisol, so it does not explain hypercortisolism.

Excess cortisol that originates from stimulation of the adrenal cortex by ACTH is at the heart of this question. In Cushing disease, a pituitary adenoma makes too much ACTH, which drives the adrenal cortex to produce and release more cortisol than normal. That direct pituitary source of ACTH leading to adrenal cortisol overproduction is why Cushing disease is the best answer for a pituitary-driven cause of hypercortisolism.

It's worth noting that Cushing syndrome is the broader term for high cortisol levels from any cause—pituitary (Cushing disease), ectopic ACTH, adrenal tumors, or external steroid use. Addison disease is the opposite process (adrenal insufficiency, low cortisol). Pheochromocytoma involves excess catecholamines from the adrenal medulla, not cortisol, so it does not explain hypercortisolism.