Abstract
A 78-year-old male patient visited our hospital with chief complaint of an abdominal mass. Laboratory data were within normal limits except CRP and erythrocyte sedimentation rate. Drip infusion pyelography and computed tomography showed a large right renal tumor with multiple calcification. Following these examinations, he was scheduled for the operation. However, he was discharged because he did not accept operation. As he noticed the rapid growth of tumor about 2 months later, he was readmitted to our hospital. The right transperitoneal nephrectomy was carried out. There were dense adhesions to the duodenum and the colon. Four weeks after the operation he died of gastro-intestinal hemorrhage and duodeno-cutaneous fistula.
The weight of resected tumor was 3680g. In the cut surface, about one-third of the tumor was yellow in colour and soft which was close to the right renal parenchyma. The rest of the tumor was gray in colour and hard. Histologically the yellow part pf the tumor was typical clear cell carcinoma, however the gray part of the tumor was very similar to the histology of fibrosarcoma.
Reported cases of giant renal cell carcinoma in Japan weighing over 2000g were collected. Our case was the third in our country in terms of resected specimen's weight. Meanwhile, histological examination of the most part of our resected specimen showed unusual features interpreted as a sarcomatoid renal carcinoma. Previous literatures dealing with sarcomatoid renal carcinoma were reviewed and its histogenesis was discussed
