The Paris System CAP简介.docxVIP

Paris System: a new paradigm for urinary cytologyGüliz A. Barkan, MDEva M. Wojcik, MDDorothy L. Rosenthal, MDDaniel F.I. Kurtycz, MDMay 2016The Paris System Working Group has proposed and published a standardized reporting system that redefines the primary purpose of urinary cytology: the detection of high-grade urothelial carcinoma (HGUC).1?A program to address standardization of urine cytology reporting was conceived at the 18th International Congress of Cytology in Paris in May 2013 where a number of people of like interest assembled and formed the Paris System Working Group. This consortium was composed of an international group of cytopathologists, surgical pathologists, and urologists. The reporting system is grounded in the current understanding of the pathogenesis and clinical significance of urothelial carcinoma (UC).Morphology divides UC into two general groups, low grade and high grade. Not surprisingly, the two groups also have different genetic pathways and vastly different biologic behavior.2-4?Approximately 70 percent of UC arising in the urinary bladder are non-muscle invasive (WHO/ISUP stage pTaT1) papillary tumors, usually observed via cystoscopy, that are generally categorized as low-grade urothelial carcinoma (LGUC) on biopsy. They have a good prognosis but have been associated with a high recurrence rate. Although early studies have suggested up to 10 to 15 percent of LGUC progress to HGUC, current literature indicates that earlier studies5 likely overstated the amount of progression. The remaining 30 percent are muscle-invasive (≥T2) tumors, which are histologically categorized as HGUC and associated with worse overall survival than LGUC. In situ flat urothelial lesions are by definition noninvasive HGUC. Their flat nature causes them to be more difficult to detect on cystoscopy, but their high-grade cytomorphology necessitates biopsy and close follow-up.Urine cytology has a high sensitivity of detecting HGUC because the morphological features