Multiple Endocrine Neoplasia Type 1 (MEN1) Follow-up

Updated: Jan 05, 2022
  • Author: Catherine Anastasopoulou, MD, PhD, FACE; Chief Editor: George T Griffing, MD  more...
  • Print

Further Outpatient Care

Current clinical guidelines suggest that patients with multiple endocrine neoplasia type 1 undergo annual screening for pancreatic neuroendocrine tumors (pNETs), using plasma hormonal measurements and imaging studies. Screening can permit timely interventions to prevent morbidity and mortality related to metastasis. [1] See the table below.

Table. Recommended screening schedules for patients with multiple endocrine neoplasia type 1 (Open Table in a new window)


Age at which to begin screening (yr)

Blood tests (annual)

Imaging studies



Fasting glucose, insulin


Anterior pituitary


Prolactin, IGF-I

MRI (every 3 yr)



Calcium, PTH


Other pancreatic neuroendocrine tumors

< 10

Chromogranin-A; pancreatic polypeptide,

glucagon, VIP

MRI, CT, or EUS (annually)


< 10

Only in patients with symptoms or signs of a functioning tumor and/or tumor >1 cm identified

on an imaging study

MRI or CT (annually with pancreatic


Thymic and bronchial carcinoid



CT or MRI (every 1-2 yr)



Gastrin (± gastric pH)


CT = computed tomography; EUS = endoscopic ultrasound; IGF-1 = Insulin-like growth factor 1; ( MRI = magnetic resonance imaging; PTH = parathyroid hormone; VIP = vasoactive intestinal peptide

Adapted from Thakker RV, et al. Clinical Practice Guidelines for Multiple Endocrine Neoplasia Type 1 (MEN1). J Clin Endocrinol Metab. 2012 Sep. 97(9):2990-3011. [1]

Current guidelines also suggest biochemical screening of pituitary tumors, with levels of plasma prolactin (PRL) and insulinlike growth factor–1 (IGF-1) measured annually and head magnetic resonance imaging (MRI) performed every 3-5 years. [1] A nonfunctioning pituitary adenoma can cause elevation of the PRL through compression of the pituitary stalk. These nonfunctioning adenomas are not detected by annual biochemical analysis but they can grow rapidly, compressing and damaging adjacent structures. Some authors have suggested that head MRI scans should be performed every 1-2 years in all MEN1 patients. [35]




Untreated multiple endocrine neoplasia type 1 (MEN1) patients have a decreased life expectancy, with a 50% probability of death by age 50 years. The cause of death is usually associated with a malignant tumor or sequelae of the disease. [1] One multicenter study suggests that 70% of patients with MEN1 die of causes directly related to MEN1. [7]