Leukoplakia of the renal pelvis has been of increasing interest as indicated by its recognition in recent years. It is of interest to the pathologist because of its unknown pathogenesis and of clinical importance to the urologist for the diagnostic and therapeutic difficulties. It is a paradox, simulating an epithelial process (ectoderm) and yet occurring on the mucous membranes of the urinary tract, a structure of mesodermal and entodermal origin. The unsatisfactory treatment for leukoplakia, as well as the possibility of malignant degeneration, makes the condition one of clinical importance.
Leukoplakia of the renal pelvis occurs more frequently than is thought. Its infrequent occurrence is more apparent than real, the condition being overlooked through a laxity in observation of genitourinary disease. Up to the present, sixty-seven proved cases have been recorded, inclusive of the case herein reported. Of the sixty-seven cases, forty-two were recorded prior to 1923, and twenty-five cases