[Cholesteatoma of the kidney pelvis in horseshoe kidney].

This paper presents one case of cholesteatoma of the left renal pelvis of a horseshoe kidney. This is quite an unusual process presenting an uncertain etiology and originated from a escamour metaplasia of the urothelium. Diagnosis can be made by X-rays and unlike leukoplasia it is not considered to be a pre-malignant condition. Probable etiologies, diagnosis and treatment are commented.