What is MEN1 syndrome?

The key features of multiple endocrine neoplasia type 1. By Dr Keith Barnard

What is it?

  • Multiple endocrine neoplasia type 1 (MEN1) syndrome, or Wermer's syndrome, was first described in 1954 by US physician Dr Paul Wermer. It is an uncommon (1:30,000) inherited disease that affects men and women equally. Those who inherit the gene for MEN1 have an increased chance of developing overactivity, and enlargement and neoplasia of the parathyroid glands, the pancreas and the pituitary.
  • The abnormality is on the long arm of chromosome 11. It is autosomal dominant with a high degree of penetrance.

How does it present?

  • Presentation in 80% of cases is with parathyroid hyperplasia, adenomata and hyperparathyroidism. Patients develop asymptomatic hypercalcaemia on biochemical screening, or may have sporadic hyperparathyroidism.
  • Pancreatic endocrine tumours occur in about 70%, usually between 15 and 50 years of age. Most are gastrinomas that cause Zollinger-Ellison syndrome. Peptic ulcers and oesophagitis are responsible for most of the morbidity and mortality. About 30% are insulinomas. Non-functioning tumours are fairly common.
  • With both parathyroid and pancreatic disease there is diffuse hyperplasia and the pancreas usually has small multiple adenomata.
  • Screening detects pituitary adenomas in 30% of patients. There is no diffuse hyperplasia, but prolactinomas are most common, causing hyperprolactinaemia. High levels of growth hormone produce acromegaly in about 30% of cases.
  • Cushing's syndrome may occur due to excess adrenocorticotropic hormone. Other functioning tumours are rare.
  • Subtle changes in the skin occur in as many as 90% of cases. There may be lipomas, collagenomas and multiple angiofibromas.

Making the diagnosis

  • MEN1 should be considered in a patient with features of hyperparathyroidism or increased gastric acid production. If another family member is affected, screening may detect undiagnosed cases.
  • Screening of firstand second-degree relatives can detect parathyroid, pancreatic or pituitary lesions. Early detection helps in morbidity, but does not seem to affect mortality. Screening should include checking serum calcium, fasting gastrin and prolactin.

Managing MEN1

  • Drug treatment includes diazoxide to inhibit insulin release, PPIs in high dosage for gastrin-secreting tumours, and pituitary hormone replacement after surgery.
  • Surgical treatment includes parathyroidectomy, but there is a high rate of recurrence. Pituitary tumours are treated by transsphenoidal excision. Surgery for pancreatic tumours is controversial and varies from complete excision of the pancreas and duodenum to removal of large lesions.
  • Genetic counselling is needed.
  • The prognosis for parathyroid and pituitary tumours is good, and pancreatic tumours are less malignant than sporadic tumours, with median survival of 15 years (only five years for sporadic tumours).
  • Dr Barnard is a former GP in Fareham, Hampshire

Have you registered with us yet?

Register now to enjoy more articles and free email bulletins


Already registered?

Sign in

Just published


Government confirms £2.45 core pay uplift to support 6% practice pay rise

Global sum payments per weighted patient will rise from £102.28 to £104.73 for 2023/24...

Nurse giving elderly man the flu vaccination

Flu vaccination prevented 25,000 hospitalisations last year

Health officials are urging vulnerable people to come forward for their flu jab after...

BMA strikes

Public blame government for long NHS waits as three-day strike begins

Three times as many people blame the government for the record 7.7m NHS waiting list...

GP typing at computer

GP practices asked to switch on data sharing with UK Biobank

GP practices have been asked to share patient data with the biomedical database UK...

Child vaccination

'Serious concern' as child vaccination rates slip and MMR hits new low

Health officials have voiced 'serious concern' after child vaccination rates in England...

Talking General Practice logo

Podcast: GP contract trends, the future of physician associates, cost-of-living impact on patient health

The team discusses what recent tenders for GP contracts tell us about the possible...