We report a case of giant benign renal cyst that was treated with percutaneous aspiration and sclerotherapy using 95% alcohol. A 8F catheter was inserted into the cyst under ultrasonographic (US) guidance, and was then left in place to drain the cyst contents (approximately 4 L). A gravity sinogram showed no connections between the cyst and the collecting system. The alcohol treatment involved repeated injections of decreasing amounts of alcohol according with US measurement of cystic volume. The patient's symptoms resolved and cyst drainage stopped after 3 successive days of therapy. Follow-up ultrasound studies showed a 3.5 cm residual cystic wall only.
