[Unusual clinical presentations of tumours of the renal pelvis. Report of two cases ].

Chronic irritation induced by stones and urinary stasis can be responsible for squamous and sometimes glandular metaplasia of the urothelial epithelium with secondary carcinomatous transformation. The authors report two cases of tumour of the renal pelvis associated with stone pyonephrosis in one case and ureteropelvic junction syndrome in the other.