[A Case of Primary Synovial Sarcoma of the Abdominal Wall].

We report a case of a 51‒year‒old man who presented with right lower abdominal pain. On physical examination, a palpable, tender mass was detected in the right lower abdomen. Contrast‒enhanced computed tomography (CT) revealed a 15‒cm mass in the right lower abdominal wall, supplied by the right inferior epigastric artery, with internal hemorrhage and necrotic areas. Radiological findings were inconclusive for malignancy. As there was no evidence of distant metastasis or invasion into adjacent organs, the tumor was considered resectable, and surgical resection was performed. Histopathological examination confirmed the diagnosis of synovial sarcoma. Given the high risk of recurrence and metastasis associated with synovial sarcoma, adjuvant chemotherapy was administered postoperatively. The patient remains alive without recurrence 1 year after surgery.