Multiple Endocrine Neoplasia (MEN) Syndromes
MEN syndromes are a group of autosomal dominant disorders characterized by tumors in multiple endocrine organs. Remembering the association of specific tumors with specific genes is high-yield for exams.
1. MEN Syndrome Comparison
| Syndrome | Key Associations | Gene Mutation |
|---|---|---|
| MEN 1 | “3 Ps”: Parathyroid, Pancreas, Pituitary. | MEN1 (Menin) |
| MEN 2A | Medullary Thyroid, Pheochromocytoma, Parathyroid. | RET |
| MEN 2B | Medullary Thyroid, Pheochromocytoma, Marfanoid habitus, Mucosal neuromas. | RET |
2. Exam Must-Knows
- MEN 1: Frequently presents with primary hyperparathyroidism first. Pancreatic tumors (e.g., gastrinoma/Zollinger-Ellison) are common.
- MEN 2 (2A vs 2B): Both have medullary thyroid carcinoma and pheochromocytoma. Only 2A has hyperparathyroidism. Only 2B has marfanoid habitus/neuromas.
Pathology Board Hint: For test questions, remember: MEN 1 = 3 Ps. MEN 2A = 2Ps (Parathyroid, Pheo) + Thyroid. MEN 2B = 1P (Pheo) + Thyroid + Neuromas. If you see a medullary thyroid carcinoma patient, always screen for RET mutations and check for pheochromocytoma before surgery to avoid a hypertensive crisis.