Cholesteatoma in ectopic kidney.

Cholesteatoma in the urinary system is a rarely seen benign condition. Rosina firstly defined this condition in the year 1953. Histopathologically it is characterized with keratinization, and squamous metaplasia of urothelial epithelium associated with desquamation of keratinized layers. Flank pain is the most common symptom that is caused by elimination of keratinous material. In our case we will discuss cholesteatoma developed in an ectopic kidney which has not been described in the literature before.