A case of "acquired cystic disease of the kidney" with renal cell carcinoma

A 24 year-old man was first noted proteinuria in (17 year-old). At the time, his serum creatinine was 2.8 mg/dl and intravenous pyelography revealed normal size kidney without cyst. Renal biopsy was compatible with the findings of rapidly progressive glomerulonephritis. In, he was placed on intermittent hemodialysis. In, he suddenly complained of macroscopic hematuria and fever, Since computerized tomography suggested polycystic kidney and abscess, bilateral nephrectomy was performed in The left kidney was 244 g in weight and the right kidney with hematoma weighed 458 g. Numerous cysts up to 2 cm in diameter were noted both in the cortex and the medulla. Numerous cysts lined with cuboidal cells and tumors invariably arose from the lining epithelium of the cysts. Tumor cells were composed of two types: clear cells and eosinophilic granular cells, Invasive clear cell carcinoma was found in the limited area adjacent to the hematoma. These findings suggested the tumor had the multicentric development. Our case is not congenital polycystic kidney because of negative family history of polycystic kidney and biopsy proved glomerulonephritis as his original disease. Recently, Dunnill et al, reported "acquired cystic disease of the kidney" and suggested high incidence and high risk of malignancy in such patients. We believe that this is the first report of "acquired cystic disease" in Japan. Only twenty cases of "acquired cystic disease" has been reported in the literatures. Eight out of 20 cases showed tumor, and one had renal cell carcinoma with systemic metastasis. Our case is the second report of renal malignancy occurring in "acquired cystic disease". While the numbers of long-term survival on hemodialysis are increasing rapidly, this entity will be of great importance because of high incidence of the disease itself and frequent complication of carcinoma.