DianaPB,
The urothelium - the transitional epithelium - the "TC" of "TCC" - is a continuous lining of the bladder, the ureters and the renal pelvis (and parts of the urethra).
TCC - Transitional Cell Carcinoma can appear anywhere within that continuum, without being considered as metastasis, and are generally referred to as "bladder cancer". They are discussed as bladder cancer.
Next upstream of the renal pelves are the kidneys.
Best,
Jack