stage 0 transitional cell carcinoma in situ of the renal pelvis and ureter

Abnormal cells are found in tissue lining the inside of the renal pelvis or ureter. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is divided into stages 0a (papillary carcinoma) and 0is (carcinoma in situ), depending on the type of tumor. Stage 0a may look like tiny mushrooms growing from the lining of the renal pelvis or ureter. Stage 0is is a flat tumor on the tissue lining the inside of the renal pelvis or ureter.