[Bilateral renal cell carcinoma of dialysis patient manifesting as spontaneous renal rupture].

A 50-year-old male had been maintained on hemodialysis for 12 years because of chronic renal failure. The patient experienced sudden left flank pain. Computed tomography (CT) showed a huge left perirenal hematoma, which was diagnosed as a spontaneous rupture of the left kidney. CT also showed multiple cysts in both kidneys and a right renal tumor suspected to be renal cell carcinoma. Although the cause of the rupture was unknown, bilateral nephrectomy was performed. Histological study revealed acquired cystic disease of the kidney (ACDK) with bilateral renal cell carcinoma. Our diagnosis was rupture of the renal cell carcinoma. The patient was free of recurrence at 17 months postoperatively. To our knowledge, this case is the fifth report of renal cell carcinoma in ACDK manifesting as spontaneous rupture in the Japanese literature.