Diagnostic ultrasound of polypoid cystitis in dogs.

Polypoid cystitis is a rare disease of the urinary bladder in dogs characterized by chronic inflammation, epithelial proliferation, and development of a polypoid mass or masses without histopathologic evidence of neoplasia. The ultrasonographic appearances of eight dogs with polypoid cystitis are described. Ultrasonography confirmed the presence of a bladder mass or masses in all patients. Ultrasonographic findings are mucosal projections and a polypoid to pedunculated mass of variable size and shape. Although a polypoid mass tends to be located in the cranioventral bladder mucosa, the polyps also could arise in the craniodorsal bladder mucosa. Ultrasonographic images are well correlated with contrast radiographic studies and gross morphological appearance. Ultrasound is a non-invasive, very useful diagnostic tool for detecting bladder polyps, but histopathology is required for definitive diagnosis.