History
A 10-year-old castrated male Shetland Sheepdog was referred for evaluation of a mass in the urinary bladder. The dog had a 1-month history of pollakiuria, stranguria, and hematuria and was initially treated by the referring veterinarian with antimicrobials, which resulted in clinical improvement. Clinical signs returned, and a second course of antimicrobials was instituted with the same results. The dog was reevaluated by the referring veterinarian who performed abdominal ultrasonography, which revealed a large mass in the urinary bladder filling an estimated two thirds of the lumen. At this time, the dog was started on piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h).
On physical examination, the dog was bright, alert, responsive, and seemingly healthy. Vital parameters were within reference limits. Biochemical abnormalities included slightly high BUN (28.3 mg/dL; reference range, 10 to 25 mg/dL), serum glucose (103 mg/dL; reference range, 80 to 100 mg/dL), and serum cholesterol (334 mg/dL; reference range, 68 to 224 mg/dL) concentrations and a low serum creatinine kinase (67 U/L; reference range, 92 to 357 U/L) activity. None of these findings were considered clinically relevant. Urine specific gravity was 1.021. Urinalysis performed with a reagent strip revealed that the dog had proteinuria (1+; scale, negative to 4+), hematuria (3+; scale, negative to 3+), and bilirubinuria (1+; scale, negative to 3+). Urine sediment contained a moderate number of nucleated cells and many erythrocytes. Nucleated cells were transitional epithelial cells with moderate atypia. Anisocytosis, anisokaryosis, a few binucleated cells, and rare mitotic figures were also observed. No abnormalities were found on CBC. Three-view thoracic radiography revealed no evidence of metastatic disease. An ultrasonographic image of the urinary bladder was obtained (Figure 1).
Transverse (A) and longitudinal (B) ultrasonographic images of the urinary bladder in a 10-year-old dog evaluated for a 1-month history of pollakiuria, stranguria, and hematuria. Marks with numbers on the right side of the images indicate centimeters.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
Transverse (A) and longitudinal (B) ultrasonographic images of the urinary bladder in a 10-year-old dog evaluated for a 1-month history of pollakiuria, stranguria, and hematuria. Marks with numbers on the right side of the images indicate centimeters.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
Transverse (A) and longitudinal (B) ultrasonographic images of the urinary bladder in a 10-year-old dog evaluated for a 1-month history of pollakiuria, stranguria, and hematuria. Marks with numbers on the right side of the images indicate centimeters.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
Determine whether additional imaging studies are required, or make your diagnosis from Figure 1—then turn the page →
Diagnostic Imaging Findings and Interpretation
A large cystic mass in the urinary bladder is filling most of the lumen with a focal area of attachment to the bladder wall away from the trigone (Figures 2 and 3). Differential diagnoses for the mass include malignant and benign neoplasms and polypoid cystitis.1 Reported neoplasms consist of transitional cell carcinoma (TCC), squamous cell carcinoma, adenocarcinoma, fibrosarcoma, leiomyosarcoma, rhabdomyosarcoma, and lymphosarcoma.1,2 The most commonly diagnosed neoplasm is TCC.2
Same ultrasonographic images as in Figure 1. Notice the multiple cysts associated with the mass (red arrows). The mass is located away from the trigone of the bladder (yellow arrow). See Figure 1 for remainder of key.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
Same ultrasonographic images as in Figure 1. Notice the multiple cysts associated with the mass (red arrows). The mass is located away from the trigone of the bladder (yellow arrow). See Figure 1 for remainder of key.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
Same ultrasonographic images as in Figure 1. Notice the multiple cysts associated with the mass (red arrows). The mass is located away from the trigone of the bladder (yellow arrow). See Figure 1 for remainder of key.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
A longitudinal color flow Doppler ultrasonographic image reveals the blood supply entering through a stalk-like projection (green arrow) and the cystic mass (red arrow). See Figure 1 for remainder of key.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
A longitudinal color flow Doppler ultrasonographic image reveals the blood supply entering through a stalk-like projection (green arrow) and the cystic mass (red arrow). See Figure 1 for remainder of key.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
A longitudinal color flow Doppler ultrasonographic image reveals the blood supply entering through a stalk-like projection (green arrow) and the cystic mass (red arrow). See Figure 1 for remainder of key.
Citation: Journal of the American Veterinary Medical Association 235, 12; 10.2460/javma.235.12.1403
Comments
Often a tentative diagnosis of TCC can be made from signalment, history, and ultrasonographic findings. Breeds commonly affected include Scottish Terriers, Shetland Sheepdogs, Beagles, Wire Fox Terriers, and West Highland White Terriers.1–4 As with many forms of cancer, affected dogs tend to be older. Females are more likely to be affected than males. Historical findings typically include pollakiuria, stranguria, hematuria, and antimicrobial treatment that temporarily relieved or at least improved clinical signs.1,2,4 A urinalysis may reveal neoplastic cells in 30% of dogs with TCC; however, these cells often cannot be differentiated from reactive epithelial cells resulting from inflammation.2,4 Ultimately, histologic examination of the mass is needed to make a definitive diagnosis.
In the dog of this report, both the signalment and history were in accordance with a diagnosis of TCC; however, results of the abdominal ultrasonography were not as clear. Typical ultrasonographic findings include a mass that is often located in the trigone of the bladder with ureteral involvement.2 Ultrasonographic images of the urinary bladder of this dog suggested that the mass was pedunculated and away from the trigone. This suspected TCC was also unusual in that its ultrasonographic appearance resembled a cluster of grapes, which is more characteristic of polypoid cystitis.
Transitional cell carcinomas in dogs are often managed medically because of their nonresectable location or because of the presence of metastatic disease. Surgery has often been regarded as unrewarding with short survival times (median, 106 days) because local recurrence or development of a distant lesion often occurs even with tumors that have had grossly complete resection.2–4 Recurrence is likely the result of the purported field effect of exposure of the entire urinary bladder mucosa to carcinogens. The potential for tumor transplantation or seeding within the urinary bladder or the abdomen also exists with exfoliated TCC cells in the urine or on contaminated instruments or gloves.5 On the basis of ultrasonographic findings, surgery was recommended for diagnostic and possibly therapeutic intent in this dog. Because the mass was pedunculated, not located in the trigone of the bladder, and lacked evidence of metastasis, complete excision of the mass appeared possible. If the mass were diagnosed as polypoid cystitis or a benign neoplasm, the potential for surgical cure existed.6
Unfortunately, the neoplasm in this dog could not be completely resected with only approximately 85% of the mass removed. The mass was closer to the trigone of the bladder than originally thought and did incorporate 1 ureteral orifice. It was also observed during surgery that the neoplasm was fragmenting and poorly organized, which was presumably a response to the piroxicam and could potentially explain the unusual ultrasonographic appearance. Histologic examination of the mass confirmed that the neoplasm was a TCC. Adjuvant treatment recommendations were to continue piroxicam (0.3 mg/kg, PO, q 24 h) and to add mitoxantrone (5 mg/m2, IV, q 3 wk for 4 treatments).
- 2.↑
Knapp DW. Tumors of the urinary system. In: Withrow SJ, Vail DM, eds. Withrow and MacEwen's small animal clinical oncology. Philadelphia: WB Saunders Co, 2007;649–657.
- 3.
Mutsaers AJ, Widmer WR, Knapp DW. Canine transitional cell carcinoma. J Vet Intern Med 2003;17:136–144.
- 4.
Henry CJ. Management of transitional cell carcinoma. Vet Clin North Am Small Anim Pract 2003;33:597–613.
- 5.↑
Gilson SD, Stone EA. Surgically induced tumor seeding in eight dogs and two cats. J Am Vet Med Assoc 1990;196:1811–1815.
- 6.↑
Martinez I, Mattoon JS, Eaton KA, et al. Polypoid cystitis in 17 dogs (1978–2001). J Vet Intern Med 2003;17:499–509.
