[A case of renal carcinoma with bone metastasis, producing alpha-fetoprotein]

A 54-year-old man was admitted with the complaint of severe lumbago, pain in the right shoulder and difficulty in walking. Laboratory tests showed markedly increased alpha-fetoprotein (AFP) level (600 ng/ml) and tomography demonstrated osteolytic lesion of the 5th lumbar vertebra and right scapula. Needle biopsy of the 5th lumbar vertebra revealed only necrotic tissue pathologically. Liver scan and whole body CT did not show any abnormality except for a right renal mass. Hypervascular tumor at the lower pole of the right kidney was noted by IVP and selective renal angiography. No pulmonary metastasis was found. The patient underwent transabdominal right nephrectomy. He had a lowered level of AFP (300 ng/ml) on the 17th post operative day. AFP level dropped further to 100 ng/ml after administration of vinblastine and ifosfamide. Lumbago continued without improving, and the patient died at home 20 weeks after surgery due to general weakness. Although we did not perform radiological examination of gastro-intestinal tract or autopsy, we concluded that renal cancer and/or a metastatic lesion to bone produced AFP because of the following reasons. No other tumor was detected by liver scan, whole body CT, laboratory examinations, operation or clinical symptoms. The AFP level was lowered after nephrectomy, and further dropped with chemotherapy. A case of renal cancer with bone metastasis and without liver metastasis, producing AFP was reported in the Japanese literature in 1983.