[Percutaneous treatment of a renal pelvis-calyx cholesteatoma].

A 54-year-old women reported recurrent pain in one side. Radiological and ultrasonographic examination revealed a mass in the left renal pelvis and the lower calyx. With percutaneous calycopyeloscopy keratinous fragments of a cholesteatoma were found and extracted during the same procedure. Up to now, malignant degeneration of a cholesteatoma has never been reported in the literature. Therefore, a conservative surgical treatment is acceptable.