[Benign hemorrhagic renal cyst diagnosed by endoscopic biopsy: a case report].

A case of benign renal hemorrhagic cyst in a 73-year-old man is reported. Ultrasonography, computed tomography and magnetic resonance imaging revealed a solid mass in the left renal cyst. Percutaneous puncture of left renal cyst was carried out followed by endoscopic biopsy of the intracystic masses. Specimens showed no malignancy. As we could not rule out malignancy, left partial nephrectomy was performed. The surgical specimen was free from malignancy by pathological examination. Thus endoscopic biopsy of intracystic tumor indicated the correct diagnosis.