{"id":4422642,"date":"2025-01-12T08:48:02","date_gmt":"2025-01-12T14:48:02","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/men-1\/"},"modified":"2025-01-12T08:59:04","modified_gmt":"2025-01-12T14:59:04","slug":"men-1","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/men-1\/","title":{"rendered":"MEN 1"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Overview of MEN1<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition &amp; Prevalence<\/strong>\n<ul class=\"wp-block-list\">\n<li>Rare autosomal dominant disorder<\/li>\n\n\n\n<li>Estimated incidence: ~2 per 100,000<\/li>\n\n\n\n<li>Characterized by neoplasms in the pituitary, parathyroid, and pancreas<\/li>\n\n\n\n<li>May also involve adrenal glands, duodenum (gastrinoma), and thoracic organs (carcinoid tumors)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Genetics<\/strong>\n<ul class=\"wp-block-list\">\n<li>Caused by mutations in the MEN1 tumor suppressor gene, which encodes the protein menin<\/li>\n\n\n\n<li>Most individuals inherit one mutated MEN1 allele from an affected parent<\/li>\n\n\n\n<li>Tumor formation requires a second, somatic inactivation (\u201ctwo-hit\u201d hypothesis) of the remaining normal allele in each susceptible endocrine cell<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Common Endocrine Tumors in MEN 1<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Parathyroid Hyperplasia\/Adenomas<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Most common feature<\/strong> (100% penetrance by age 50)<\/li>\n\n\n\n<li>Presentation: <a href=\"https:\/\/myendoconsult.com\/learn\/topics\/primary-hyperparathyroidism\/\"  data-wpil-monitor-id=\"303\">Primary hyperparathyroidism<\/a> (hypercalcemia + inappropriately high PTH)<\/li>\n\n\n\n<li>Treatment: Surgical removal of 3.5 parathyroid glands; sometimes further reoperations or ethanol injections if recurrent hypercalcemia<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/topics\/nonfunctioning-pituitary-adenoma\/\"  data-wpil-monitor-id=\"304\">Pituitary Adenomas<\/a><\/strong>\n<ul class=\"wp-block-list\">\n<li>Occur in ~20% of patients with MEN 1<\/li>\n\n\n\n<li><a href=\"https:\/\/myendoconsult.com\/learn\/topics\/prolactinoma\/\"  data-wpil-monitor-id=\"305\">Prolactinoma is most frequent pituitary<\/a> tumor; GH- or ACTH-secreting adenomas also possible<\/li>\n\n\n\n<li>Management: Similar to sporadic pituitary adenomas (medical therapy with dopamine agonists for prolactinomas, or surgery\/radiation as indicated)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Gastroenteropancreatic (GEP) Tumors<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Major source of morbidity and mortality<\/strong> in MEN 1<\/li>\n\n\n\n<li>Commonly found in the duodenum or pancreas; may be multiple and malignant<\/li>\n\n\n\n<li><strong>Gastrinomas (Zollinger-Ellison syndrome)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Often small and multifocal, typically in the duodenum<\/li>\n\n\n\n<li>Cause severe peptic ulcer disease, especially if combined with hypercalcemia<\/li>\n\n\n\n<li>Proton pump inhibitors effectively control acid hypersecretion<\/li>\n\n\n\n<li>Surgical resection if feasible, especially if identified during a pancreatic operation<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Pancreatic islet tumors<\/strong>\n<ul class=\"wp-block-list\">\n<li>May secrete insulin, glucagon, vasoactive intestinal polypeptide (VIP), or pancreatic polypeptide (PP)<\/li>\n\n\n\n<li>Insulinomas can be small and numerous; resection for symptomatic ones<\/li>\n\n\n\n<li>Nonfunctioning pancreatic tumors \u22652 cm warrant surgical resection (risk of malignancy rises with size)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Additional Features<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Other Tumors<\/strong>\n<ul class=\"wp-block-list\">\n<li>Adrenal tumors (often nonfunctioning)<\/li>\n\n\n\n<li>Lung and thymic carcinoids<\/li>\n\n\n\n<li>Esophageal leiomyomas<\/li>\n\n\n\n<li>Spinal cord ependymomas (rare)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Cutaneous Manifestations<\/strong>\n<ul class=\"wp-block-list\">\n<li>Angiofibromas (small vascular lesions on face\/body)<\/li>\n\n\n\n<li>Collagenomas (dermal nodules)<\/li>\n\n\n\n<li>Lipomas (subcutaneous fatty growths)<\/li>\n\n\n\n<li>These lesions are benign but can be numerous<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Screening &amp; Management<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Clinical Suspicion<\/strong>\n<ul class=\"wp-block-list\">\n<li>Combination of two or more primary MEN 1 tumors (parathyroid, pituitary, or GEP tumors)<\/li>\n\n\n\n<li>Family history of MEN 1\u2013related neoplasms<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Genetic Testing<\/strong>\n<ul class=\"wp-block-list\">\n<li>MEN1 germline mutation analysis for high-risk individuals<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Biochemical Monitoring<\/strong>\n<ul class=\"wp-block-list\">\n<li>Annual blood tests for hypercalcemia (PTH, calcium), pituitary hormones (prolactin, IGF-1, etc.), and GEP tumor markers (gastrin, glucagon, VIP, pancreatic polypeptide, chromogranin A)<\/li>\n\n\n\n<li>Imaging (MRI, endoscopic ultrasound) for tumor localization<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Therapeutic Approaches<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Parathyroid tumors<\/strong>: Surgical resection (3.5 glands) to manage hyperparathyroidism<\/li>\n\n\n\n<li><strong>Pituitary adenomas<\/strong>: Medical (dopamine agonists), surgical, or radiotherapy, depending on hormone secretion and size<\/li>\n\n\n\n<li><strong>GEP tumors<\/strong>: Proton pump inhibitors for Zollinger-Ellison syndrome; resect symptomatic or large pancreatic tumors<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Overview of MEN1 Common Endocrine Tumors in MEN 1 Additional Features Screening &amp; Management<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[690],"class_list":["post-4422642","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-rare-genetic-conditions","post-wrapper","thrv_wrapper"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422642","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":3,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422642\/revisions"}],"predecessor-version":[{"id":4422645,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422642\/revisions\/4422645"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422642"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422642"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}