Multiple endocrine neoplasia type 1

This diagnosis is typified by hyperparathyroidism, pituitary tumours and pancreatic tumours, and may be confirmed by finding a mutation in the MENIN gene.

Screening at diagnosis

At diagnosis of MEN1, patients should undergo genetic testing, full blood count, urea and electrolytes, liver function, bone profile for calcium, parathyroid hormone, baseline pituitary function including prolactin, and fasting gut hormones.

Chest radiograph, CT pancreas and MRI pituitary are also performed at diagnosis. Imaging is not repeated routinely in MEN1 patients, unless clinically indicated by new symptoms, or a rise in pituitary or gut hormones.


Each complication of MEN1 should be investigated and treated in the standard way for that condition. See management of hypercalcaemiaprolactinoma, Cushing’s, acromegaly, non functioning pituitary adenomas, insulinomas, neuro-endocrine tumours.

Annual follow up

All patients with confirmed MEN1 should be followed up on an annual basis life long to detect and treat complications.

Annual screen

This should include: reassessment of family history, full blood count, urea and electrolytes, liver function test, bone profile, fasting glucose, fasting gut peptides and prolactin.

Further imaging

Chest radiograph should be repeated every three years.

CT pancreas and MRI pituitary should be repeated if clinically indicated.

Imaging and follow-up must be repeated more frequently when lesions are detected.

Family members

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