Multiple endocrine neoplasia type 2
Multiple endocrine neoplasia type 2 (also known as "Pheochromocytoma (codons 630 and 634) and amyloid producing medullary thyroid carcinoma", "PTC syndrome," and "Sipple syndrome") is a group of medical disorders associated with tumors of the endocrine system. The tumors may be benign or malignant (cancer). They generally occur in endocrine organs (e.g. thyroid, parathyroid, and adrenals), but may also occur in endocrine tissues of organs not classically thought of as endocrine. MEN2 is a sub-type of MEN (multiple endocrine neoplasia) and itself has sub-types, as discussed below. Variants in MEN2A have been associated with Hirschsprung disease. Screening for this condition can begin as young as eight years old for Pheochromocytoma. Signs and symptoms MEN2 can present with a sign or symptom related to a tumor or, in the case of multiple endocrine neoplasia type 2b, with characteristic musculoskeletal and/or lip and/or gastrointestinal findings. Medullary thyroid carcinoma (MTC) represents the most frequent initial diagnosis. Occasionally pheochromocytoma or primary hyperparathyroidism may be the initial diagnosis. Pheochromocytoma occurs in 33-50% of MEN2 cases. In MEN2A, primary hyperparathyroidism occurs in 10–50% of cases and is usually diagnosed after the third decade of life. Rarely, it may present in childhood or be the sole clinical