[Renal cell carcinoma in acquired cystic disease of the kidney manifested by spontaneous renal hemorrhage].

Acquired cystic disease of the kidney (ACDK) is a common phenomenon in long-term adult dialysis patients with end-stage renal disease. Renal hemorrhage and neoplastic transformation of the cyst are two major complications of this entity and these two can occur independently. Here we describe a 65-year-old man with a history of hemodialysis-dependent end-stage renal failure for 12 years presented with macroscopic hematuria and right flank pain. Investigations revealed right massive perirenal and subcapsular hematoma with ACDK. The hemorrhagic state required nephrectomy of the right kidney. Histological study showed ACDK with massive subcapsular and perinephric hematoma containing minimal clear cell carcinoma region(0.5 cm in diameter). Although a causal relationship between renal hemorrhage and renal cell carcinoma in this patient was unproven, the present case suggests radical surgery can be a recommendable treatment modality of hemorrhagic ACDK.