Accuracy of Urine Cytology and the Significance of an Atypical Category

Abstract

The "atypical urothelial cell" cytologic category is nonstandardized. We subclassify atypical cases to "atypical, favor a reactive process" or "atypical, unclear if reactive or neoplastic." We evaluated the predictive significance of atypical cases by looking at their histologic follow-up. Among the 1,114 patients and 3,261 specimens included, 282 specimens had histologic follow-up. An atypical diagnosis did not carry a significant increased risk of urothelial neoplasia compared with the benign category. Although an "atypical unclear" diagnosis carried a higher rate of detection of high-grade cancer on follow-up biopsy in comparison with "atypical reactive" or "negative" diagnoses (26/58 [45%] vs 15/52 [29%] and 16/103 [15.5%], respectively), this difference was not statistically significant. These results suggest that dividing atypical cases into 2 categories based on the level of cytologic suspicion of cancer does not add clinically relevant information within the atypical category. They also raise the question of the significance of the atypical category altogether.

Clinical Value of Dividing False Positive Urine Cytology Findings into Three Categories: Atypical, Indeterminate, and Suspicious of Malignancy

“…The reported rate of suspicious urine cytology ranges from 1.9% to 28.7%, (Bhatia et al, 2006;Raab et al, 2007;Kapur et al, 2008;Brimo et al, 2009;Mokhtar et al, 2010) and the rate in our study (5.6%) fell within this range. This wide range reflects the fact that the category of false positive urine cytology is poorly defined, unlike, for example, the atypical category for squamous cells in the Bethesda system, for which the diagnostic criteria are well defined and for which guidelines exist for the proportion of cases that should fall into that category.…”

“…In a study of 282 urine cytology samples with followup data, Brimo et al (Brimo et al, 2009) analyzed the association of cytology with histology in atypical urine cytology and analyzed subgroups designated as "atypical, unclear if reactive or neoplastic" and "atypical, favor a reactive process." Their results showed that compared to a benign diagnosis, a diagnosis of "atypical urothelial cells" was not associated with a significantly increased risk of UC.…”

The application of the Johns Hopkins Hospital Template on urine cytology

“…The study by Brimo et al also showed a similar pattern of sensitivity and specificity of 46.3% and 85%, respectively, if AUC-US was considered as negative and 82% and 45.4% if AUC-US was considered as an abnormal result. 10 The cytologic features of HGUC were well preserved with the liquid-based SurePath preparation. 11 In our laboratory, the most important cytologic feature of high-grade urothelial lesions, hyperchromasia, was well visualized on the SurePath slides that also contributed to the high correlation of AUC-H and HGUC with high-grade urothelial lesions in the followup biopsies.…”

Multiprobe Fluorescence in situ Hybridization (UroVysion) for the Detection of Urothelial Carcinoma – FISHing for the Right Catch

“…However, cytology performs weakly in low-grade UC due to an overlap of cytological features with benign urothelial cells. In addition, there is a commonly used but poorly defined category of atypical cytology that has questionable significance [9,10,11]. …”