Implementation of the Paris system versus institutional diagnosis in the performance of urinary cytology: A 5 years correlative study of 74 cases

Abstract

Urine cytology used for diagnosing high-grade urothelial carcinoma (HGUC), but plagued by low sensitivity and wide inter-observer variability mainly ascribed to the lack of an established template of reporting. We assessed the performance of urine cytology by comparing the Paris System with our current institutional system. This study is developed to identify the prevalence of various cytological categories and their association with a subsequent diagnosis of high-grade urothelial carcinoma. Materials and Methods : A total of seventy four urine cytological specimens were studied which have follow up biopsy with histological correlation was done to categorize: benign, atypical urothelial cells (AUCs), suspicious for high-grade urothelial carcinoma (SHGUC), and high-grade urothelial carcinoma (HGUC). Original cytological diagnoses were recorded. Results: Males outnumbered females with a mean age of 57.4 years (range 21-86) (46 M and 28 F) with no statistical significance among the age groups and between male and female genders. By applying TPS, number of cases assigned to AUC category are very few (7 cases out of 74 with 9.45. Using the TPS resulted in a higher number of low-grade carcinomas assigned to the benign rather than the AUC category.LGUN category includes all low grade urothelial neoplasms of urinary tract, such as LGUC and PUN of uncertain malignant potential. According to institute diagnosis categories for urine cytology, there were 2 cases shown negatives, 16 cases shown Atypical/suspicious, 21 cases shown LG papillomas, and 35 cases shown HGUC. In negative group; out of 2 cases, 2 cases were papilloma. In HGUC group, out of 35 cases, 27 cases were turned out to be HGUC with 77.14%. In HGUC group, out of 35 cases, 8 cases were turned out to be LGUP with 29.62%. Conclusion:The TPS seems to improve the performance of urine cytology by limiting the AUC category to cases that are more strongly associated with HGUC. This is the first inclusive attempt at standardizing urinary cytology.

A comparison between conventional and the Paris systems of reporting urinary cytopathology with a literature update

“…Interestingly, Vallamreddy et al 23 reported an unusually high number of LGUNs (17/77) on urine cytology by TPS, all of which turned out to be either a low-grade urothelial papilloma (LGUP) or papillary urothelial neoplasm of undetermined malignant potential (PUNLMP), which we consider an exceptional situation. 23 Cystoscopic examination, capable of better identifying LGUNs, plays a complementary role in the cytologic detection of LGUNs. 48…”

“…Two urine samples interpreted as “LGUC” in the CS group had histologic concordance, while two of each of the remaining four cases interpreted as “suspicious of LGUC” turned out to be “LGUC” and “HGUC,” respectively. Interestingly, Vallamreddy et al 23 reported an unusually high number of LGUNs (17/77) on urine cytology by TPS, all of which turned out to be either a low‐grade urothelial papilloma (LGUP) or papillary urothelial neoplasm of undetermined malignant potential (PUNLMP), which we consider an exceptional situation 23 . Cystoscopic examination, capable of better identifying LGUNs, plays a complementary role in the cytologic detection of LGUNs 48 …”

“…for UroVysion, while its sensitivity was as low as 42% against an 83% sensitivity for UroVysion-FISH. 31 The Paris system (TPS), introduced in 2015, has gained wide popularity within a fairly short period, [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] with its 2022 version providing updated information based on the post-TPS experience. 28 A recent meta-analysis of all the eligible post-TPS data has come out with an estimation of the pooled risk of high-grade malignancy (ROHM) for various TPS categories, which are as follows: 17.70% for the nondiagnostic category; 13.04% for the NHGUC; 38.65% for the AUC; 12.45% for the LGUN; 76.89 for the SHGUC; and 91.79% for the HGUC and other malignancies.…”

“…The Paris System for reporting urinary cytology (TPS), published in 2015 by a working group comprising cytopathologists, surgical pathologists, and urologists, became the first universal, standardized system for reporting urinary cytology. The main aim of TPS was to facilitate better patient management by formulating rigid cytomorphologic criteria for diagnosing high‐grade urothelial carcinoma (HGUC) and minimizing the rate of reporting “atypical urothelial cells (AUC).” 11 Since its implementation, several studies have evaluated the merits and limitations of TPS 12–27 . The recently updated second edition of TPS incorporated changes based on the 6‐year post‐TPS literature available 28 …”

International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer. Working Group 1

“…A systematic review of reports pertaining to TPS was performed with 27 studies included in the literature review (Table 3). 27–53 The studies which compared the cytology findings against tumor grade used the designation of “low” or “high” grade similar to WHO 2004. The cohort size was variable in each study (median: 149, range: 57 to 3900).…”