Multiple endocrine neoplasia type 2

MEN2 or Sipple's syndrome is caused by the ret oncogene and has three forms. The diagnosis usually refers to MEN2a, comprising medullary thyroid cancer (MTC), phaeochromocytoma and parathyroid tumours. MEN2b comprises MTC, phaeochromocytoma, Marfanoid habitus and mucosal ganglionneuromatosis. Isolated familial medullary thyroid cancer is also caused by ret mutations.

Screening at diagnosis

At first presentation of an affected individual or family member, family history should be documented, and genetic screening should be arranged. If this confirms disease, or if it is not available, a full clinical screen should be arranged.

This should include full blood count, urea and electrolytes, liver function, bone profile, PTH, calcitonin, baseline pituitary function, and 2x24 hour urinary metanephrines. Chest radiograph, neck ultrasound scan and CT adrenals should also be performed for disease staging at this point.

Complications of MEN2 should be treated in the usual way

See management sections of phaeochromocytoma, hyperparathyroidism and thyroid nodules for further information. The detailed management of medullary cell carcinoma is beyond the scope of this guide.

Annual screen

Annual screen should include: re-assessment of family history, full blood count, urea and electrolytes, liver function test, bone profile, fasting glucose, calcitonin, prolactin, 2x24hr urinary metanephrines, and PTH if serum calcium is elevated. Chest radiograph and CT adrenals should be repeated every three years routinely. Imaging and follow-up must be repeated more frequently when lesions are detected.

All first degree relatives should be followed up in the same way as confirmed cases, unless genetic screening is negative.

All patients with confirmed MEN2 should be followed up annually to detect further complications and re-assess family history

Life long follow up is mandatory.