All bladder tumor diagnoses are not cancerous, according to the National Institutes of Health. Some bladder tumors are benign. One type of benign tumor found in the urinary bladder is called a glomus tumor. These tumors are quite rare.
Other benign tumors found in the bladder are urothelial tumors, according to the Canadian Cancer Society. These are papillomas, or small growths, that appear in the inner lining of the wall of the bladder. People who have these papillomas may have trouble urinating or may have blood in the urine. Since blood in the urine is also a sign of bladder cancer, according to Mayo Clinic, the person should see his doctor.