Which of the following is the most common functional adrenocortical tumor in adults?

Explanation

## Functional Adrenocortical Tumors: Epidemiology **Key Point:** Aldosterone-secreting adenomas (Conn's syndrome / Primary Hyperaldosteronism) are the most common functional adrenocortical tumors in adults, accounting for approximately 60–70% of all cases of primary hyperaldosteronism and representing the single most frequent functional cortical tumor type. ### Relative Frequency of Functional Adrenocortical Tumors | Tumor Type | Frequency | Clinical Syndrome | Key Features | |---|---|---|---| | Aldosterone-secreting adenoma | Most common | Primary hyperaldosteronism (Conn's) | Hypertension, hypokalemia, suppressed renin | | Cortisol-secreting adenoma | Second most common | Cushing's syndrome | Suppressed ACTH, autonomous cortisol production | | Androgen-secreting adenoma | Rare | Virilization / feminization | More common in children; often malignant | | Pheochromocytoma | Not adrenocortical | Catecholamine excess | Arises from adrenal medulla (chromaffin cells), NOT cortex | **High-Yield:** According to Schwartz's Principles of Surgery and Harrison's Principles of Internal Medicine, aldosterone-secreting adenomas are the most common functional adrenocortical tumors in adults. Primary hyperaldosteronism (Conn's syndrome) is now recognized as the most common cause of secondary hypertension, with aldosterone-producing adenomas accounting for the majority of cases. **Clinical Pearl:** Note that pheochromocytoma (Option B) is technically NOT an adrenocortical tumor — it arises from chromaffin cells of the adrenal medulla, not the cortex. Among true adrenocortical functional tumors, aldosterone-secreting adenomas rank first, followed by cortisol-secreting adenomas. **Why Option A is incorrect:** While cortisol-secreting adenomas are a significant cause of adrenal incidentalomas, they are less frequent than aldosterone-secreting adenomas as a functional adrenocortical tumor type. The prevalence of primary hyperaldosteronism (largely due to aldosterone-producing adenomas) is estimated at 5–10% of all hypertensive patients, making it far more common in clinical practice. **Mnemonic:** **ACAP** — Aldosterone (most common functional adrenocortical tumor), Cortisol (second), Androgen (rare), Pheochromocytoma (medullary, not cortical). *Reference: Schwartz's Principles of Surgery, 11th ed.; Harrison's Principles of Internal Medicine, 21st ed.*