Odd-looking Bladder Mass with a Stalk
Emily Evans BVM&S
Age: 10 year old
Gender: Male Neutered
Breed: Pit Bull
Patient had a 3 week history of stranguria, frequent urination and hematuria. Antibiotic therapy (Amoxicillin for 2 weeks) resulted in no improvements. A caudal abdominal mass was palpated on recheck exam.
A large (~4.0x3.6cm), round, heterogenous hypoechoic, vascular mass is seen occupying the bladder lumen with a thick hyperechoic wall(<0.3cm). A vascular, hyperechoic stalk(~0.5cm thick) extended from the caudal aspect of the mass into the proximal urethra at the level of the prostate. The mass filled most of the partially full bladder but appeared non-obstructive. The remainder of the bladder had normal thickness, contour and there were no uroliths seen. There was no evidence of structural change in the kidneys. The prostate had a normal size (1.1cm in diameter), shape and echogenicity.
Diagnosis and Sonographic Analysis:
Tumors of the urinary bladder are uncommon in dogs. Transitional cell carcinoma (TCC) is the most common primary tumor of the urinary bladder. Other differentials include squamous cell carcinoma, leiomyosarcoma, leiomyoma, and rhabdomyosarcoma or benign bladder polyp. The bladder may also be invaded by prostatic neoplasia or metastatic disease (e.g., hemangiosarcoma, lymphoma).
Most TCCs have a more invasive appearance than the mass in this case, typically causing irregularity of the bladder wall in the trigone. TCCs are not limited to the bladder trigone and can begin anywhere in the bladder, urethra, kidneys and prostate.
An oncology consultation was pursued and therapy was initiated for a presumed TCC. The patient was started on Piroxicam and Mitoxantrone along with a repeat course of antibiotics. He has showed continued improvement and the hematuria has fully resolved. He still has frequent urination but everyone is pleased with his progression. A recheck ultrasound is scheduled for later this month.
Special thanks to Battlefield Veterinary Clinic of Sandston, VA and The Oncology Service at Dogwood Veterinary Emergency and Speciality Center.