Renal cell carcinoma in a multilocular renal cyst: a case report of a 27-year-old female and review of the literature.

A case of renal cell carcinoma in a multilocular renal cyst is reported. Excretory urography showed a mass, and ultrasound revealed multiple renal cysts in the middle part of the left kidney. This finding could also be visualized by computer tomography, a solid structure could not be detected. During operation a 6-cm multiloculated cyst was enucleated from the left kidney. A frozen section of the cystic lesion did not indicate a malignancy; however, further histopathological examination revealed a renal cell carcinoma, especially in the septal parts of the tumor.