Endocrine Neoplasia: Clinical Features and Management

Introduction to Endocrine Neoplasia

Endocrine neoplasia refers to tumors that develop in hormone-producing tissues, with Multiple Endocrine Neoplasia (MEN) syndromes representing hereditary forms characterized by tumors in multiple endocrine glands, each with distinct genetic causes and clinical manifestations 1

MEN1 is an autosomal dominant disorder caused by pathogenic variants in the MEN1 gene, characterized by parathyroid adenomas, pancreatic islet tumors, and anterior pituitary neuroendocrine tumors 1, 2
HPT-JT Syndrome is caused by pathogenic CDC73 variants, characterized by parathyroid tumors and ossifying fibromas of the jaw 1, 4
Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of tumors originating from neuroendocrine cells of the embryological gut 5, 6

Primary hyperparathyroidism is the most common presenting feature of MEN1, occurring in 95% of patients 7, 8
MEN1 patients may also present with pancreatic islet tumors, anterior pituitary tumors, dermatologic manifestations, adrenocortical adenomas, and other manifestations 7
Disease penetrance in MEN1 is 45% by age 30, 82% by age 50, and 96% by age 70 7
Primary hyperparathyroidism is also a common feature of MEN4, occurring in 100% of reported cases 3

The WHO classification of GEP-NETs includes NET G1, NET G2, NEC G3, and mixed adenoneuroendocrine carcinoma (MANEC) 6
Diagnosis of endocrine neoplasia requires histopathological confirmation, immunohistochemistry, Ki-67 proliferation index assessment, genetic testing, biochemical evaluation, and imaging studies 1, 5, 6, 8

Pre-symptomatic screening of at-risk individuals allows earlier detection and intervention 1
Surveillance recommendations differ by syndrome type and should begin in childhood for hereditary forms 1
MEN2 surveillance timing depends on specific RET mutation and risk classification 4
MEN4 surveillance should focus on hyperparathyroidism and pituitary tumors 3
HPT-JT surveillance should include screening for parathyroid tumors, jaw tumors, and renal anomalies 4