Renal pelvic biopsies of renal calculi patients.

Histological alterations in the renal pelves of 32 patients operated on for renal stone(s) were investigated in this prospective study. It was demonstrated that there were five cases of squamous metaplasia, two cases each of pyelitis cystica, pyelitis follicularis and polypoid pyelitis, and one case each of papillary adenocarcinoma, transitional cell carcinoma and encrusted pyelitis. The results obtained suggest that renal pelvic biopsy should be a routine procedure during open or percutaneous renal surgery.