[Retroperitoneal malignant schwannoma: a case report].

A 56-year-old woman was admitted with a complaint of a palpable left abdominal mass. The left kidney was compressed by the tumor which measured 18 x 10 cm in size on computed tomographic scanning. We diagnosed a left renal tumor or retroperitoneal tumor. No metastatic lesions were detected. We performed radical nephrectomy with complete tumor resection on August 28, 1997. The tumor had two satellites and was adherent to the renal capsule. A yellowish-white solid tumor was macroscopically encapsulated by fibrous tissue and had cystic lesions filled with bloody fluid, weighed 940 g and was 18 x 11 x 8 cm in size. Histopathological diagnosis was malignant schwannoma. No lymphnode metastases were observed. For poor responsiveness to chemotherapy and radiation therapy in this type of tumor, we did not perform adjuvant therapy. The patient is alive with no evidence of recurrence more than four years after surgery.