Which statement best describes Cushing disease?

Which statement best describes Cushing disease?

• A. Cushing disease is ACTH-secreting pituitary adenoma causing hypercortisolism.
• B. Cushing disease includes exogenous steroids as a cause.
• C. Cushing disease is adrenal tumor producing cortisol.
• D. Cushing disease is cortisol deficiency.

Answer: (A)

Cushing disease is defined by a pituitary source of excessive ACTH that drives the adrenal cortex to overproduce cortisol, leading to hypercortisolism. This makes it the pituitary-driven form of Cushing syndrome. The other scenarios describe different origins of excess cortisol: taking external steroids causes Cushing syndrome from exogenous sources, an adrenal tumor causes cortisol overproduction directly from the adrenal gland (often with suppressed ACTH), and cortisol deficiency is the opposite state.

Cushing disease is defined by a pituitary source of excessive ACTH that drives the adrenal cortex to overproduce cortisol, leading to hypercortisolism. This makes it the pituitary-driven form of Cushing syndrome. The other scenarios describe different origins of excess cortisol: taking external steroids causes Cushing syndrome from exogenous sources, an adrenal tumor causes cortisol overproduction directly from the adrenal gland (often with suppressed ACTH), and cortisol deficiency is the opposite state.