Which tumor constellation is characteristic of MEN 2A?

• A. Pheochromocytoma, Medullary thyroid carcinoma, Primary hyperparathyroidism
• B. Pituitary adenoma
• C. Adrenal cortical adenoma
• D. Pheochromocytoma, Medullary thyroid carcinoma, Pituitary adenoma

Answer: (A)

Understanding MEN 2A: it is defined by a distinctive tumor cluster of pheochromocytoma, medullary thyroid carcinoma, and primary hyperparathyroidism. This triad comes from a germline RET mutation and is the classic presentation of MEN2A, also known as Sipple syndrome. Pheochromocytoma arises from the adrenal medulla, medullary thyroid carcinoma from C cells, and hyperparathyroidism from parathyroid hyperplasia or adenoma.

Pituitary adenoma points to MEN1, not MEN2A, while an adrenal cortical adenoma is not part of MEN syndromes; pheochromocytoma specifically involves the adrenal medulla. Therefore, the combination that matches MEN2A is the one including pheochromocytoma, medullary thyroid carcinoma, and primary hyperparathyroidism.