The following case is reported because it represents from a clinical and pathologic standpoint the various stages in the development of a squamous cell carcinoma of the renal pelvis. Reports of similar cases, although not frequent, illustrate the important relation of irritation1 to leukoplakia, and of continued irritation to consequent carcinomatous changes.
Kutmann1a reported a case of leukoplakia in the renal pelvis, and stated that only 67 similar unquestioned cases had been reported. Patch2 found reports of 152 cases of squamous cell carcinoma in the urinary tract; 36 renal, 6 ureteral and 10 vesical. In 13 cases, cancer and leukoplakia coexisted.
Equally interesting is the relation of calculi to the development of squamous cell tumors. Wells3 in 1922 found reports of 11 unquestioned cases of squamous cell cancer of the renal pelvis, and reported a case of his own. The presence of calculi was mentioned in