[Upper urinary tract tumors pathology (ureter, pelvis and renal calyces)].

OBJECTIVES: To show the pathologic characteristics of upper urinary tract tumors with special emphasis on the peculiarities due to anatomical site and secondary to endoscopic treatment. METHODS: Bibliographic review and presentation of our ten-year experience at the "Hospital Ramon y Cajal" Pathology Department in Madrid studying 203 urothelial tumors of the ureter, renal pelvis and calyces. RESULTS: More than 95% of the upper urinary tract tumors in adults have their origin in the urothelium, and most of them are either malignant or potentially malignant. Their biological behaviour is similar to bladder tumors, although they have some peculiarities due to their anatomical localization. Tumors at the renal calyces may be more aggressive due to their particular way of intrarenal dissemination. CONCLUSIONS: Anatomical localization and proper pathological study are the determinant factors to establish prognosis and possible adjuvant treatment for upper urinary tract tumors after endoscopic resection.