Transitional cell carcinoma, also called urothelial carcinoma, is a type of cancer that typically occurs in the urinary system. It is the most common type of bladder cancer and cancer of the ureter, urethra, and urachus. Symptoms of urothelial carcinoma in the bladder include hematuria (blood in the urine). Diagnosis includes urine analysis and imaging of the urinary tract (cystoscopy). Transitional cell carcinomas arise from the transitional epithelium, a tissue lining the inner surface of these hollow organs. When the term "urothelial" is used, it specifically refers to a carcinoma of the urothelium, meaning a transitional cell carcinomas of the urinary system. It accounts for 95% of bladder cancer cases and bladder cancer is in the top 10 most common malignancy disease in the world and is associated with approximately 200,000 deaths per year in the US. It is the second most common type of kidney cancer, but accounts for only five to 10 percent of all primary renal malignant tumors. Men and older people have a higher rate of urothelial carcinomas. Other risk factors include smoking and exposure to aromatic amines. Treatment approaches depend on the stage and spread of the tumour. Tumour removal (resection), chemotherapy and chemoradiation may be indicated. Immunotherapy with immune check point inhibitor medications may also be suggested.

Reference
Wiki: Bladder transitional cell carcinoma