The patient underwent surgery and in view of the possibility of renal pelvis malignancy consent was given for nephroureterectomy. Cystoscopy was done first and there was no bladder tumour. A pyelolithotomythrough a lumbar approach was done, showing marked thickening of the perirenal tissues with a lot of chronic inflammatory changes of the renal pelvis. The stone was extracted and there were no macroscopic signs of malignancy in the renal pelvis. This was confirmed by histology which show chronic inflammation and fatty necrosis but no but no malignancy. The postoperative course was uneventful.