Diagnosis and Management of Multiple Endocrine Neoplasia Type 1 (MEN1)

Abstract

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominantly inherited disorder, characterised by the occurrence of tumours of the parathyroid glands, the pancreatic islets, the pituitary gland, the adrenal glands and neuroendocrine carcinoid tumours. Carcinoid tumours of the thymus and pancreatic-duodenal gastrinomas are the most harmful tumour types, since these tumours have malignant potential and curative treatment is difficult to achieve.MEN1 is caused by germline mutations of the MEN1 tumour suppressor gene. Mutation analysis enables mutation carriers to be identified. MEN1 patients and their family members, family members of mutation carriers and patients who are clinically suspected to be carriers of a MEN1 gene mutation are eligible for mutation analysis. MEN1-associated tumours can be detected and treated at an early stage through periodical clinical monitoring of mutation carriers.

Figure 1

Recommendations for diagnosis and management of parathyroid adenomas (A), pancreatic islet cell tumours (B), and pituitary adenomas (C) in MEN1 patients. PTH: parathyroid hormone; CT: computed tomography; ZES: Zollinger-Ellison syndrome; WDHA: watery diarrhoea, hypokalemia, achlorhydria; VIP: vasoactive intestinal peptide; NFT: non-functioning tumour; PRL: prolactin; GH: growth hormone; ACTH: adrenocorticotrophic hormone; SA: somatostatin analogues.

Figure 2

(A) CT imaging of a 42-year-old MEN1 patient. A lesion is present in the mediastinum (indicated with green arrows). The lesion turned out to be a carcinoid tumour of the thymus. Due to invasive growth into the pleura the tumour could not be completely removed. (B) Chest CT of the same patient, five years later. The tumour in the upper mediastinum has expanded; there is compression of the trachea. The patient died from respiratory failure