Urothelial carcinoma is a type of cancer that originates in the urothelium, the tissue lining the bladder and other parts of the urinary tract. It is the most common form of bladder cancer and can also occur in the ureters and renal pelvis. Risk factors include smoking, exposure to certain chemicals, and chronic bladder irritation. Symptoms of urothelial carcinoma may include blood in the urine, frequent urination, and pain during urination. Diagnosis typically involves imaging tests, cystoscopy, and biopsy. Treatment options often include surgery, chemotherapy, and immunotherapy, depending on the stage and grade of the cancer.