A case report of primary mucinous adenocarcinoma of the thymus and review of the literature.

Thymic mucinous adenocarcinoma is an extremely rare and aggressive malignant tumor of the thymus with a very low 5-year survival rate. Here, we report a case of surgically resected primary mucinous adenocarcinoma of the thymus in a patient in his 60s who was admitted to the hospital with chest tightness for 2 weeks. The patient underwent median sternotomy and thymectomy, including resection of the brachiocephalic vein and partial resection of the superior vena cava wall. Histopathologic examination confirmed the diagnosis of mucinous adenocarcinoma, staged as pT2aN2M0 (IVB). Immunohistochemical analysis showed negative expression of CK20 and CK7, and preoperative carcinoembryonic antigen levels were within the normal range.