Thymoma (World Health Organization Type AB) in multiple endocrine neoplasia type 1: a case report

Thymic neoplasms are rarely seen among patients with multiple endocrine neoplasia type 1 (MEN1) and appear to be especially rare when pathological examination reveals a World Health Organization Type AB thymoma. In the case presented here, we report a 39-year-old woman with Type AB thymoma in MEN1. A 7.8-cm-sized mediastinal mass was diagnosed as a thymic neoplasm by computed tomography. In addition, pituitary tumor and hypercalcemia from parathyroid hyperplasia were found. Therefore, the patient was clinically diagnosed with MEN1 syndrome and underwent surgical resection of thymic tumor. At the 1-year follow-up, the patient appeared to be healthy without any sign of reoccurrence. Despite its rare occurrence, our case provides us with a new awareness that thymoma may coexist with MEN1.