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

Abstract

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