[Multiple endocrine neoplasia type 2a and 2b].

Multiple endocrine neoplasia type 2a and 2b (MEN 2a and 2b) are rare diseases, inherited as autosomal dominant traits. The neoplasias in MEN 2a are medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism. In MEN 2b a characteristic phenotype is seen in combination with medullary thyroid carcinoma and pheochromocytoma. Through screening the diseases can be detected at an early stage, hereby improving prognosis. This is important as the diseases are inherited and occur in young individuals. In this review, epidemiology, clinical features, diagnosis and treatment are discussed.