4th April 2024

MEN-1

Background

Primary hyperparathyroidism is present in approximately 90% of patients. 40 to 70% of patients have functioning or non-functioning pancreatic neuroendocrine tumours, which include insulinomas, gastrinomas, VIPomas, and somatostatinomas. Pituitary adenomas are present in 30 to 40% of MEN-1 patients.

Patients, therefore, may present with symptoms of hyperparathyroidism and of a pituitary adenoma. Hyperparathyroidism leads to hypercalcaemia manifesting as ‘bones, stones and groans’. These symptoms are the most common presenting feature. Those with pituitary adenomas may have symptoms of hyperprolactinaemia (erectile dysfunction, infertility, galactorrhoea, headaches), acromegaly, hyperthyroidism and hypercortisolism. Pituitary adenomas cause both visual and endocrinologic symptoms. Patients may experience gradual vision loss, hyperprolactinaemia (erectile dysfunction, infertility, galactorrhoea, headaches), acromegaly, hyperthyroidism and hypercortisolism.

Diagnosis

The criteria for diagnosis involve any one of the following:

• Two or more MEN-1 associated endocrine tumours 
• One or more MEN-1 associated tumours and a first degree relative with MEN-1
• MEN1 mutation

Treatment

Treatment is focused on medical management of the manifestations of MEN and consideration of surgical removal of tumours.