16- MULTIPLE ENDOCRINE NEOPLASIA

• Multiple Endocrine Neoplasia (MEN) I

  • Associated with Menin tumor suppressor gene on chromosome 11
  • Parathyroid adenoma à hypercalcemia
  • Pituitary adenoma à prolactinoma, Cushing's, acromegaly
  • Pancreatic islet cell tumors à Insulinoma, Gastrinoma, VIPoma, Glucagonoma
  • May also be associated with cutaneous tumors and carcinoid
• Screening for MEN I

  • Hyperparathyroidism is the earliest manifestation, and serum Ca is the best way to screen families
  • Other methods: prolactin, GH/IGF-1, gastrin & pancreatic enzymes
  • Imaging: periodic imaging of pancreas, adrenal and pituitary
• Multiple Endocrine Neoplasia (MEN) II

  • Associated with RET protooncogene mutation on chromosome 10
  • 2 types: MEN IIA & MEN IIB
  • Both MEN IIA & MEN IIB have Pheochromocytoma and Medullary thyroid cancer
  • MEN IIA: Parathyroid hyperplasia (à high calcium)
  • MEN IIB: Mucosal neuroma lips, tongue, GI) and Marfanoid (slim body habitus)
• Screening for MEN II

  • Screen asymptomatic family members with ret genetic testing
  • Hyperparathyroidism: serum ca
  • Pheochromocytoma: metanephrine or catecholamine
  • Medullary thyroid carcinoma: total thyroidectomy is recommended in early childhood once the genetic mutation identified, Calcitonin work as tumor marker