Abstract
A 64-year-old male with end-stage renal disease who had been on hemodialysis since March 2000 was referred to us after abdominal ultrasound screening demonstrated a right renal mass. The patient had a past history of right partial nephrectomy for renal hemorrhage 45 years before. CT and MRI showed bilateral atrophic kidneys with cysts (acquired cystic disease of the kidney: ACDK) and a renal tumor of 4cm in diameter in the lower pole of the right kidney. However, it was difficult to differentiate renal cell carcinoma from hematoma by diagnostic imaging. The patient underwent right radical nephrectomy under a preoperative diagnosis of suspected renal cell carcinoma of ACDK. The pathological diagnosis of the surgical specimen was intra-cystic hematoma (hemorrhagic cyst). Most of the reported cases of renal hematoma in patients on hemodialysis were complicated with ACDK, and could easily be distinguished from renal cell carcinoma by CT and MRI. Image findings in this case were considered very rare. Because of the high rate of renal cell carcinoma complicated with hematoma and also of the high incidence of renal cell carcinoma in ACDK, we chose radical nephrectomy in this case.
