A benign neoplasm of the bladder that involves the transitional epithelium projecting above the surrounding epithelial surface and consisting of villous or arborescent outgrowths of fibrovascular stroma. The disease is MONDO_0044906 (bladder urothelial papilloma). Also known as: bladder transitional cell papilloma, urinary bladder transitional cell papilloma, urinary bladder urothelial papilloma.