What is the most common cause of Cushing Syndrome?

What is the most common cause of Cushing Syndrome?

• A. Steroid-based medications
• B. Adrenal adenoma
• C. Pituitary ACTH-secreting tumor
• D. Ectopic ACTH production

Answer: (A)

Prolonged exposure to glucocorticoids from prescribed steroid medications is the most common cause of Cushing syndrome. Exogenous steroids produce the signs and symptoms of hypercortisolism, and their continual use suppresses the body's own ACTH production through negative feedback. As a result, endogenous cortisol production falls, making endogenous sources like adrenal tumors or ACTH-producing tumors less likely to be the primary cause when there is a history of long-term steroid use. If no steroid exposure is present, endogenous causes—pituitary ACTH-secreting tumors or ectopic ACTH production, or an adrenal cortisol-secreting tumor—are considered and investigated with ACTH levels and suppression testing.

Prolonged exposure to glucocorticoids from prescribed steroid medications is the most common cause of Cushing syndrome. Exogenous steroids produce the signs and symptoms of hypercortisolism, and their continual use suppresses the body's own ACTH production through negative feedback. As a result, endogenous cortisol production falls, making endogenous sources like adrenal tumors or ACTH-producing tumors less likely to be the primary cause when there is a history of long-term steroid use. If no steroid exposure is present, endogenous causes—pituitary ACTH-secreting tumors or ectopic ACTH production, or an adrenal cortisol-secreting tumor—are considered and investigated with ACTH levels and suppression testing.