A 45-year-old woman is found to have a medullary thyroid carcinoma. Genetic testing reveals a germline gain-of-function mutation in the RET proto-oncogene. This mutation is associated with which hereditary syndrome and additional tumor risk?
- A MEN2A — pheochromocytoma and parathyroid hyperplasia ✓
- B MEN1 — parathyroid adenoma and pituitary adenoma
- C MEN2B — pheochromocytoma and marfanoid habitus
- D VHL syndrome — renal cell carcinoma and hemangioblastoma
Correct answer: A. MEN2A — pheochromocytoma and parathyroid hyperplasia
Explanation
RET gain-of-function mutations cause both MEN2A and MEN2B. MEN2A (Sipple syndrome) specifically combines medullary thyroid carcinoma, pheochromocytoma, and parathyroid hyperplasia/adenoma. MEN2B also involves RET mutations with pheochromocytoma but features mucosal neuromas and marfanoid habitus instead of parathyroid disease. MEN1 is caused by MEN1 (menin) gene mutations, and VHL by VHL tumor suppressor mutations.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.