Multiple endocrine neoplasia(MEN)is an autosomal dominantly inherited tumor syndrome which develop tumors in multiple endocrine organs and its subtype, MEN1 and MEN2, are well known. The causative gene for MEN1 is the MEN1 gene located on chromosome 11q13. Primary hyperparathyroidism, pancreatic gastroduodenal neuroendocrine tumor, pituitary tumor, adrenal cortical hyperplasia, or thymic neuroendocrine tumor are the typical features of MEN1 patients. Pathogenic variant of the MEN1 gene is distributed in exons 2-10. The causative gene for MEN2 is the RET gene located on chromosome 10q11.2. MEN2 is characterized by medullary thyroid carcinoma, pheochromocytoma and primary hyperparathyroidism. MEN2 is divided into two clinical phenotypes, 2A and 2B. Pathogenic variant of the RET gene concentrated on exons 10, 11, 13-16 and there are strong association of the location of the pathogenic variant with disease phenotype. Recently, it is reported that the pathogenic variant of the CDKN1B gene located on chromosome 12p13 is the cause of MEN4. In this syndrome, MEN1- associated tumors of hyperparathyroidism, pituitary adenomas and neuroendocrine tumors of the pancreas or digestive tract with other endocrine tumors are found. The onset age is relatively high and it shows greater diversity of the tumors compared to MEN1.
Adenoma Adrenal Gland Neoplasms