Which of the following are secondary causes of adrenal insufficiency?

• A. Pituitary tumors
• B. Hypophysectomy
• C. Abrupt discontinuation of corticosteroids
• D. All of the above

Answer: (D)

Secondary adrenal insufficiency occurs when the pituitary cannot provide enough ACTH to stimulate the adrenal cortex, or when the hypothalamic-pituitary axis is suppressed. Each of these scenarios fits that pattern.

Pituitary tumors reduce ACTH production, so the adrenal cortex isn’t adequately stimulated and cortisol falls, while aldosterone is usually preserved because its regulation by ACTH is minimal and the renin-angiotensin system keeps mineralocorticoid function intact.

Hypophysectomy, the surgical removal of the pituitary, directly eliminates the source of ACTH, leading to deficient cortisol production with preserved aldosterone.

Abrupt discontinuation of corticosteroids after long-term therapy suppresses the HPA axis; the body’s own ACTH/cortisol production remains suppressed for a time, producing insufficient cortisol when the exogenous steroids are stopped.

Thus, all of these scenarios can cause secondary adrenal insufficiency, making “all of the above” the correct choice.