OBJECTIVE: To investigate the diagnosis and treatment of Multiple Endocrine Neoplasia Type 1 (MEN1), improve our understanding of the disease and highlight the importance of life-long follow-up of affected individuals. METHODS: A retrospective analysis was performed on 1 MEN1 patient with long-term follow-up at the First Affiliated Hospital of Anhui Medical University. RESULTS: A 51-year-old woman was diagnosed with MEN1 14 years ago, but exhibited a suspected disease course of at least 20 years. Prior to admission, the patient reported a cough lasting for two months. The patient's thyroid hormone, sex hormone, insulin, cortisol, parathyroid hormone, and ACTH circadian rhythm findings were within normal ranges. The patient exhibited elevated blood calcium levels. Examination led to the detection of thymoma and pancreatic neoplasms, whereas no obvious abnormalities were detected in her parathyroid gland or adrenal gland as determined via computed tomography (CT). Genetic analyses revealed a mutation in the MEN1 gene in this patient. As the patient had no relevant clinical symptoms, she refused surgical treatment, and follow-up was continued. It was learned through follow-up that the patient underwent anterior mediastinal lesion resection and partial rib resection in June 2020 because she re-examined the chest CT showed that the anterior mediastinal mass was significantly larger than that in 2019. Pathology suggested neuroendocrine tumors. The patient is currently recovering well. CONCLUSION: MEN1 is an uncommon condition in clinical settings, and it is important that clinicians be made aware of this disorder so that they can provide patients with appropriate and timely treatments.