USMLE/COMLEX - Step 2 - Multiple Endocrine Neoplasia Type 2

USMLE/COMLEX - Step 2 - Multiple Endocrine Neoplasia Type 2 Multiple Endocrine Neoplasia type 2 (MEN2) is a rare genetic disorder caused by mutations in the RET proto-oncogene, leading to the development of tumors in the endocrine system. It has three subtypes MEN2A, MEN2B, and FMTC. The pathophysiology of MEN2 involves the overactivation of the RET signaling pathway, leading to the uncontrolled growth and proliferation of cells in the endocrine system. Specifically, mutations in the RET gene lead to a constitutively active RET protein, which stimulates the growth and proliferation of cells in the thyroid gland, parathyroid gland, and adrenal medulla. Medullary thyroid carcinoma: a lump in the neck, difficulty swallowing, or hoarseness. Pheochromocytoma: high blood pressure, sweating, headaches, and heart palpitations. Hyperparathyroidism: weakness, fatigue, bone pain, and kidney stones. Neuromas (in MEN2B only): tingling or numbness in the lips and tongue and gastrointestinal problems. Marfanoid habitus (in MEN2B only): tall stature, thin body type, long limbs, and joint hypermobility. Thyroid nodules or enlargement Elevated levels of calcitonin in the blood Hypertension Tachycardia Serum calcitonin levels Ultrasound, CT, or MRI scans Genetic testing for a RET gene mutation In general, the treatment options for MEN2 may include the following: 1. Thyroidectomy: Surgery to remove the thyroid gland is typically recommended for patients with medullary thyroid carcinoma. 2. Adrenalectomy: Surgery to remove one or both adrenal glands may be recommended for patients with pheochromocytoma. 3. Parathyroidectomy: Surgery to remove the parathyroid gland may be recommended for patients with hyperparathyroidism. In some cases, additional treatment, such as radiation therapy or chemotherapy, may be recommended for patients with advanced or metastatic disease. Regular follow-up care and monitoring are also recommended for patients with a history of MEN2.