RESUMEN
A 55-year-old male revealed with a 5 cm-diameter mass in the lower abdomen on ultrasonography incidentally. Computed tomography showed a mass of 7 cm in size on the left side of the bladder. A malignant tumor was suspected, and surgically excised for purpose of diagnosis and treatment. Pathological examination confirmed retroperitoneal leiomyosarcoma, and the resection margins were negative. Follow-up computed tomography scan was performed every 3 months. Repeated resections were performed for twice recurrences within a year after surgery. A year after the first surgery, lung metastasis was detected and chemotherapy was started. Although retroperitoneal leiomyosarcoma is considered to have a poor prognosis, the present case had relatively good prognosis. This may be due to early detection and repeated surgical resection.
