[Solitary infected renal cyst: a case report]

A 48-year-old man was admitted to our hospital because of high fever and left flank pain. Laboratory findings revealed a high white blood cell count, high C-reactive protein level, and severe pyuria. Sonographic examination revealed an enlargement of the cyst at the upper pole of the left kidney that had already been detected. Percutaneous drainage was performed for the cyst and 60 ml of purulent fluid was obtained. Bacterial culture of the fluid was positive for Propionibacterium acnes and gamma-Streptococcus. The drainage and administration of povidone-iodine was continued for 7 days. The size of the cyst was reduced with disappearance of symptoms.