Effects of the Paris System on the Unsatisfactory Category in a Cytohistologic Correlation Study of Patients With Urothelial Carcinoma.

Abstract

Context.—: The main objectives of the Paris System are to detect high-grade urothelial carcinoma, to standardize morphologic criteria and the cytopathologic report, to reduce the prevalence of the atypia category, and to improve the malignancy risk stratification.

Objective.—: To compare the results and sensitivity of cytologic classification before and after reclassification by the Paris System.

Design.—: Urinary cytology samples from patients with a histologic diagnosis of urothelial carcinoma were reclassified on the basis of the Paris System categories. The diagnoses before reclassification were divided into 5 categories (A, B, C, D, E) and compared with the Paris System (I, II, III, IV, V). Sensitivity was calculated considering cytohistologic agreement in relation to high-grade urothelial carcinoma.

Results.—: A total of 111 urinary cytology samples from patients were analyzed, corresponding to 40 histologic samples; of these, 12 (30%) were high grade and the remaining were low grade. Comparison of the correlated categories showed an increase from 3 (3 of 111; 2.7%) (A) to 31 (31 of 111; 27.9%) (I) in unsatisfactory cases and a decrease from 67 (67 of 111; 60,0%) to 30 (30 of 111; 27.0%) in negative cases, while the atypia category remained unchanged (15 cases [15 of 111; 13.5%]) (C and III). Suspicious cases increased from 5 (5 of 111; 4.5%) (D) to 14 (14 of 111; 12.6%) (IV) and cases of urothelial carcinoma were unchanged (21 cases [21 of 111; 18.9%]) (E and V). Sensitivity was 69% for the previous classification and 90% for the Paris System.

Conclusions.—: The Paris System improved the sensitivity of urinary cytology and the standardization of the unsatisfactory criteria, with an increase of cases in this category and a decrease of cases previously classified as negative among patients with a subsequent histologic diagnosis of urothelial carcinoma.