Long Theresa, Layfield Lester J, Esebua Magda, Frazier Shellaine R, Giorgadze D Tamar, Schmidt Robert L
Address: Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA.
Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, USA.
Cytojournal. 2017 Jul 24;14:17. doi: 10.4103/cytojournal.cytojournal_12_17. eCollection 2017.
The Paris System for Reporting Urinary Cytology represents a significant improvement in classification of urinary specimens. The system acknowledges the difficulty in cytologically diagnosing low-grade urothelial carcinomas and has developed categories to deal with this issue. The system uses six categories: unsatisfactory, negative for high-grade urothelial carcinoma (NHGUC), atypical urothelial cells, suspicious for high-grade urothelial carcinoma, high-grade urothelial carcinoma, other malignancies and a seventh subcategory (low-grade urothelial neoplasm).
Three hundred and fifty-seven urine specimens were independently reviewed by four cytopathologists unaware of the previous diagnoses. Each cytopathologist rendered a diagnosis according to the Paris System categories. Agreement was assessed using absolute agreement and weighted chance-corrected agreement (kappa). Disagreements were classified as low impact and high impact based on the potential impact of a misclassification on clinical management.
The average absolute agreement was 65% with an average expected agreement of 44%. The average chance-corrected agreement (kappa) was 0.32. Nine hundred and ninety-nine of 1902 comparisons between rater pairs were in agreement, but 12% of comparisons differed by two or more categories for the category NHGUC. Approximately 15% of the disagreements were classified as high clinical impact.
Our findings indicated that the scheme recommended by the Paris System shows adequate precision for the category NHGUC, but the other categories demonstrated unacceptable interobserver variability. This low level of diagnostic precision may negatively impact the applicability of the Paris System for widespread clinical application.
巴黎系统用于报告尿细胞学检查，代表了尿标本分类的重大改进。该系统认识到在细胞学上诊断低级别尿路上皮癌存在困难，并已制定类别来处理这一问题。该系统使用六个类别：不满意、高级别尿路上皮癌阴性（NHGUC）、非典型尿路上皮细胞、高级别尿路上皮癌可疑、高级别尿路上皮癌、其他恶性肿瘤以及第七个亚类别（低级别尿路上皮肿瘤）。
357份尿标本由4名不知先前诊断结果的细胞病理学家独立进行复查。每位细胞病理学家根据巴黎系统类别做出诊断。使用绝对一致性和加权机会校正一致性（kappa）评估一致性。根据错误分类对临床管理的潜在影响，将分歧分为低影响和高影响。
平均绝对一致性为65%，平均预期一致性为44%。平均机会校正一致性（kappa）为0.32。在评估者对之间的1902次比较中，999次一致，但在NHGUC类别中，12%的比较相差两个或更多类别。约15%的分歧被归类为具有高临床影响。
我们的研究结果表明，巴黎系统推荐的方案对NHGUC类别显示出足够的准确性，但其他类别显示出观察者间的变异性不可接受。这种低水平的诊断准确性可能会对巴黎系统在广泛临床应用中的适用性产生负面影响。
