Publication:

Diagnostic utility of the Paris system for urine cytology with histopathological correlation

Background Urothelial carcinoma (UC) is the second most common malignancy in the urogenital system. Urinary cytology is a non-invasive, cost-effective screening and monitoring technique for UC.

Methods In this retrospective study, conducted from over a period of one year, 62 urine cytology sample s were evaluated utilizing. The Paris system (TPS) for reporting urinary cytology and correlated with histopathological findings where available.

Results Urine cytological cases were divided in 5 categories as per TPS. The majority (46.77%) were negative for high-grade urothelial carcinoma (NHGUC), while 35.48% were unsatisfactory/non-diagnostic, indicating inadequate samples. 6.45% of cases were diagnosed as high-grade urothelial carcinoma (HGUC), and 4.83% were suspicious for high-grade urothelial carcinoma (SHGUC). Atypical urothelial cells (AUC) made up 6.45% of cases. No any case of low-grade urothelial neoplasm was found. Out of 62 total cases, histological correlation was available in 13. On histopathology 8 cases confirmed as UC which were diagnosed cytologically as HGUC (2 cases), SHGUC (1 case), AUC (3 cases) and NHGUC (2 cases). Two cases were nondiagnostic on cytology due to low cellularity were later reported as Sarcomatoid urothelial carcinoma with squamous component and Low-grade urothelial carcinoma each on histology. Remaining biopsies were inadequate where only necrosis and/or few atypical cells noted.

Conclusions The study highlights the effectiveness of urine cytology in detecting high-grade lesions but emphasizes the challenges posed by unsatisfactory samples and the need for a multi-modal diagnostic approach, including cystoscopy and histopathology, to enhance diagnostic accuracy. The TPS framework offers a structured method for interpreting urinary cytology, critical for improving patient outcomes in urothelial carcinoma detection.