Urothelial carcinoma, also known as transitional cell carcinoma, is the most common primary bladder tumour in dogs, and can also involve the prostate gland. Cytology is a common diagnostic tool utilized for dogs with bladder or prostate gland lesions. The objectives of this retrospective study were to compare the sensitivity and specificity of cytologic evaluation for urothelial or prostatic carcinoma between two institutions with different cytology review protocols as well as determine if certain collection methods resulted in higher cytologic accuracy. A total of 298 cases met inclusion criteria. The overall sensitivity and specificity for institution 1 were 91.8% and 50%, respectively, compared to 31.1% and 97.4%, respectively, for institution 2. When the urine sample review protocol at institution 2 was matched to that of institution 1, sensitivity and specificity were more similar to institution 1 (71.2% and 88.9%, respectively). Our results show that the sensitivity and specificity of cytology are affected by screening and review protocols implemented by different institutions. The data also demonstrate that sensitivity and specificity vary by collection method. Diagnostic catheterization had the highest performance: of the 11 cases between two institutions, it had 100% sensitivity and specificity. In contrast, examination of urine sediment not collected via diagnostic catheterization had low sensitivity and specificity that varied greatly by institution. In summary, cytologic interpretation should be undertaken with consideration given to both processing and collection protocols.
Keywords: cytology; diagnostic catheterization; histopathology; method comparison; transitional cell carcinoma.
© 2021 John Wiley & Sons Ltd.