Most patients with MEN1 present with hypercalcaemia due to primary hyperparathyroidism.
- Inherited or sporadic condition also called Wermer syndrome
- AD disorder is caused by mutations in the MEN1 gene on 11q13.
- The MEN1 gene encodes a tumour suppressor protein called MENIN
- Many are sporadic presenting in the 3rd–5th decades
Clinical (see individual topics for more information)
- Parathyroid tumours: 95%: parathyroid hyperplasia or adenoma. Primary HPTH
- Pituitary tumours: Prolactinoma or GH Secretion in about 60% of patients.
- Prolactinomas, growth hormone-producing tumours and ACTH-producing tumours.
- Galactorrhoea/infertility (due to prolactinoma), acromegaly or Cushing's disease.
- Pancreatic tumours: 50-75% of patients with MEN1 develop pancreatic islet cell tumours that include
- Gastrinoma, Insulinoma, glucagonoma and VIPoma.
- Zollinger-Ellison syndrome (due to gastrinoma often small, multicentric, and located in the duodenum)
- Watery diarrhoea with hypokalaemia and metabolic acidosis or Verner-Morrison syndrome (due to VIPoma)
- Recurrent hypoglycaemia (due to Insulinoma),
- Hyperglycaemia and necrolytic migratory erythema (due to glucagonoma).
- Occasionally: Carcinoid and adrenal tumours
- FBC, U&E, LFT, Bone
- Ca - hypercalcaemia and low/normal PTH and DEXA scan
- CT abdomen for masses. MRI head for pituitary lesions
- Endoscopy: peptic ulcer disease
- Elevated fasting gastrin level and increased basal gastric acid secretion.
- Hypoglycaemia and elevated Insulin, Elevated C-peptide and proInsulin levels
- Elevated serum glucagon levels
- Elevated serum VIP levels
- Manage tumour detected, Genetic counselling