[A Case of Primary Renal Angiosarcoma with a Rapidly Worsening Course].

A 69-year-old man presented with left flank pain and underwent a computed tomographic scan, which revealed a large left renal mass of 16×9×5 cm. A left nephrectomy was performed. Pathological analysis revealed that the tumor was consistent with angiosarcoma of the left kidney with a negative surgical margin. He received combination therapy with radiation therapy and four courses of chemotherapy with doxorubicin and ifosfamide. However, he died 10 months after surgery because of pleural dissemination and peritoneal dissemination. Primary renal angiosarcoma is an extremely rare and highly aggressive tumor with a dismal survival rate, and a satisfactory surgical margin is necessary for its successful treatment. If primary renal angiosarcoma is suspected, biopsy may be considered before surgery. Primary renal angiosarcoma treatment with combination therapy of surgery, radiotherapy, and chemotherapy by a specialist multidisciplinary team with experience and expertise in sarcoma is preferable. Development of therapy for angiosarcoma is awaited.