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 and 0is, depending on the type of tumor. Stage 0a is also called noninvasive papillary carcinoma, which may look like long, thin growths that grow out from the tissue lining the inside of the renal pelvis or ureter. Stage 0is is also called carcinoma in situ, which is a flat tumor on the tissue lining the inside of the renal pelvis or ureter.