Radiological Surveillance for Pituitary Adenomas in Multiple Endocrine Neoplasia Type 1: A Longitudinal Cohort Study

CONTEXT: Patients with multiple endocrine neoplasia type 1 (MEN1) are genetically predisposed to developing tumors of the parathyroid, pancreas, and anterior pituitary. While widespread genetic testing has increased early diagnoses, the value of radiological surveillance for pituitary adenomas in these patients remains unclear. OBJECTIVE: To investigate the impact of pituitary magnetic resonance imaging (MRI) findings on patient management in MEN1. DESIGN: Retrospective longitudinal cohort study. SETTING: NIH Clinical Center. PATIENTS: Genetically confirmed MEN1 evaluated between 1977 and September 2024. MEASURES: Cumulative proportion and rate of intervention for nonfunctional adenomas. RESULTS: Three hundred twenty patients with a mean follow-up duration of 14 ± 12 years were identified. One hundred eighty-two out of 320 patients (57%) had pituitary adenomas, of whom 95/182 (52%) had nonfunctional adenomas. All patients with adenoma had biochemical evaluation at the time of pituitary MRI. There were 21/95 (22%) patients with nonfunctional adenomas that needed an intervention throughout their follow-up. The rate of intervention per 100 patient-years for nonfunctional adenomas was 3.1% (confidence interval 2.0-4.7%). All patients with nonfunctional adenoma who required an intervention reported symptoms or had an abnormal pituitary function test. Tumor volume of 38/48 (79%) nonfunctional adenomas followed over a mean of 8.3 ± 6.1 years remained stable. Only 42/518 (8.1%) MRIs for nonfunctional adenomas were prompted by clinical or biochemical abnormalities. Individualized imaging could have avoided approximately 4 MRIs per patient with nonfunctional microadenoma over their follow-up. CONCLUSION: In an overwhelming majority of patients with MEN1, radiological surveillance for nonfunctional pituitary adenomas offers minimal added benefit beyond patient-reported symptoms and pituitary function testing.