Apex of the bladder. This dog has a transitional cell carcinoma in the bladder wall.There is a large, irregularly bordered, broad-based, mineralized mass at the apex of the urinary bladder. There is loss of wall layering adjacent to this mass.There is blood flow detected within this mass. The trigone is within normal limits.Refs: Cohn and Cote, Clinical Veterinary Advisor-Dogs and Cats, 4th ed. pp. 991-2. Radiographic interpretation and images courtesy, Dr A. Zwingenberger and Veterinary Radiology.