Utility of The Paris System for Reporting Urinary Cytology in patients with HPV-positive urinary tract carcinoma.

Background: Human papillomavirus (HPV)-positive urinary tract carcinomas (UTCas) have distinct morphology and molecular features with potential treatment implications. Cytomorphologic analysis of these tumors on urine cytology specimens has not yet been reported. The authors evaluated the cytomorphologic findings of HPV-positive UTCa on urine cytology using The Paris System for Reporting Urinary Cytology (TPS) criteria.

Methods: HPV-positive cases were identified by a retrospective review of surgical specimens that had UTCa confirmed by HPV in situ hybridization. Cases that had concurrent urine cytology were reviewed using TPS. Cytomorphologic features of high-grade urothelial carcinoma (HGUC) were evaluated as well as the presence of atypical squamous cells (ASCs) and basaloid features.

Results: Sixteen cytology specimens from eight patients with HPV-positive UTCa were included. On original diagnosis, none of the cytology specimens were suggested to be HPV-associated. TPS diagnostic criteria identified eight cases with at least atypical findings, including five HGUC cases, one case that was suspicious for HGUC, and two atypical urothelial cases. Common cytomorphologic features included basaloid clusters (six of eight cases; 75%) and ASCs (four of eight cases; 50%) that matched the corresponding surgical specimens. Most cases exhibited urothelial cell hyperchromasia (seven of eight cases; 88%), and hypochromasia was a frequently observed variant (four of eight cases; 50%), either alone or in addition to hyperchromasia.

Conclusions: HPV-positive UTCa can be identified reliably as HGUC by using TPS criteria; however, these cases may not be recognized as HPV-associated. The presence of basaloid cells or ASCs can help suggest screening for HPV in urine specimens. Larger scale studies are warranted to validate cytomorphologic differences and determine the impact of HPV infection on clinical outcomes for patients with UTCa.