Last reviewed: 25 Sep 2021
Last updated: 12 Oct 2021



History and exam

Key diagnostic factors

  • young age (MEN1/2)
  • positive family history (MEN1/2)
  • episodic triad of sweating, palpitations, and headache (MEN2)
  • clinical features of kidney stones (MEN1/2)
  • facial angiofibromas or collagenomas (MEN1)
  • mucosal neuromas (MEN2B)
  • arm span and upper-to-lower-body-segment ratio (MEN2B)
  • palpable thyroid nodule (MEN2)
  • irregular menses (MEN1)
  • visual changes (MEN1)
  • unexplained flushing (MEN2)
  • infertility (MEN1)
  • clinical features of acromegaly (MEN1)
  • clinical features of thyrotoxicosis (MEN1)

Other diagnostic factors

  • weight changes (MEN1/2)
  • hypertension (MEN1/2)
  • abdominal pain (MEN1/2)
  • headache (MEN1/2)
  • low-trauma fractures (MEN1)
  • altered bowel habit (MEN1/2)
  • palpitations (MEN1/2)
  • easy bruising (MEN1/2)
  • slow wound healing (MEN1/2)
  • erectile dysfunction (MEN1)
  • clinical features of hypercortisolism/Cushing's syndrome (MEN1/2)
  • anxiety (MEN1/2)
  • heat intolerance (MEN1)
  • confusion (MEN1/2)
  • dehydration (MEN1/2)
  • gastrointestinal bleeding (MEN2)
  • hepatomegaly (MEN2)

Risk factors

  • familial cases of MEN
  • RET proto-oncogene mutation
  • MEN1 (menin) mutation

Diagnostic investigations

1st investigations to order

  • serum calcitonin (MEN2)
  • serum carcinoembryonic antigen (MEN2)
  • plasma metanephrines (MEN2)
  • serum parathyroid hormone and calcium (MEN1/2)
  • fasting serum gastrin (MEN1)
  • serum chromogranin A (MEN1)
  • serum prolactin (MEN1)
  • insulin-like growth factor-1 (MEN1)
  • 24-hour urine metanephrines and catecholamines (MEN2)
  • 24-hour urine calcium (MEN1/2)
  • thyroid biopsy (MEN2)

Investigations to consider

  • fasting serum glucose/insulin (MEN1)
  • serum C peptide (MEN1)
  • calcium-stimulated gastrin (MEN1)
  • serum proinsulin (MEN1)
  • serum pancreatic polypeptide (MEN1)
  • serum glucagon (MEN1)
  • T4 (free thyroxine) (MEN1)
  • thyroid-stimulating hormone (TSH) (MEN1)
  • dexamethasone suppression test (MEN1/2)
  • urine sulphonylurea (MEN1/2)
  • metaiodobenzylguanidine scintiscan (MIBG) (MEN2)
  • 18F-fluorodihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET)/CT abdomen and pelvis (MEN2)
  • octreotide scan (MEN1)
  • gallium-68 DOTATATE PET/CT abdomen and pelvis (MEN1 and 2)
  • technetium 99 sestamibi scintiscan (MEN1/2)
  • abdominal CT (MEN1/2)
  • abdominal MRI (MEN1/2)
  • chest CT or MRI (MEN1)
  • pituitary MRI (MEN1)
  • endoscopic ultrasonography (MEN1)
  • upper gastrointestinal endoscopy (MEN1)
  • Helicobacter pylori breath test, biopsy, or stool antigen test (MEN1/2)

Treatment algorithm



Rebecca Gorrigan, BSc, MBChB (hons), MRCP

Consultant Physician and Endocrinologist

Department of Endocrinology

Barts and the London NHS Trust and Queen Mary University of London




RG declares that she has no competing interests.

Maralyn Druce, MA, MRCP, PhD

Professor of Endocrine Medicine

Department of Endocrinology

Barts and the London Medical School




MD has received fees for consulting from Ipsen and Novartis; their products are used in the treatment of neuroendocrine tumours. Neuroendocrine tumours of the pancreas are features of MEN1. The topic does not discuss specific therapies for features of the condition.


Dr Rebecca Gorrigan and Professor Maralyn Druce would like to gratefully acknowledge Dr Jennifer Mammen and Dr Roberto Salvatori, previous contributors to this topic.


JM and RS declare that they have no competing interests.

Peer reviewers

Michael Levine, MD, FAAP, FACP


Division of Endocrinology and Diabetes

The Children's Hospital of Philadelphia




ML declares that he has no competing interests.

Salvatore Corsello, MD

Associate Professor of Endocrinology

Catholic University School of Medicine




SC declares that he has no competing interests.

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