Undifferentiated pleomorphic sarcoma around the kidney: A case report

A 58-year-old man was incidentally found to have a left retroperitoneal tumor by computed tomography (CT) during a comprehensive health check-up and he was referred to our hospital. Enhanced CT revealed a perirenal mass located in the upper pole of the left kidney. It was diagnosed as undifferentiated/unclassified sarcoma by CT-guided needle biopsy. Laparoscopic radical nephrectomy was performed and the pathological diagnosis was undifferentiated pleomorphic sarcoma (UPS). Since the resected margin was positive, we performed adjuvant chemotherapy with doxorubicin and ifosfamide. Thereafter, the patient decided for himself to receive immunotherapy at another hospital. Unfortunately, the tumor later relapsed. Although the recurrent tumor was removed by open surgery, the resected margin was again positive. Postoperatively, the patients refused adjuvant chemotherapy and continued to receive immunotherapy. The patient then developed multiple metastases and received pazopanib which produced a temporary tumor shrinkage effect, but finally he died of disease progression.