In-situ hybridization provides a convenient and reliable method to detect human papillomavirus (HPV)
infection in
formalin-fixed
paraffin-embedded tissue. Cases of conjunctival
papillomas, conjunctival intraepithelial
neoplasia (CIN), conjunctival
carcinoma in situ (cCIS), and invasive
squamous cell carcinoma (SCC), in which low-risk (LR) and/or high-risk (HR) HPV types were evaluated by
RNA or
DNA in-situ hybridization, were retrospectively identified. LR HPV types were frequently detected in conjunctival
papillomas (25/30, 83%), including 17/18 (94%) with
RNA probes, compared to 8/12 (75%) with
DNA probes. None of the CIN/cCIS or SCC cases were positive for LR HPV by either method. HR HPV was detected by
RNA in-situ hybridization in 1/16 (6%) of CIN/cCIS cases and 2/4 (50%) of SCC cases, while
DNA in-situ hybridization failed to detect
HPV infection in any of the CIN/cCIS lesions. Reactive atypia and dysplasia observed in
papillomas was generally associated with the detection of LR HPV types. Collectively, our findings indicate
RNA in-situ hybridization may provide a high-sensitivity approach for identifying
HPV infection in squamous lesions of the conjunctiva and facilitate the distinction between reactive atypia and true dysplasia. There was no clear association between
HPV infection and atopy in
papillomas or dysplastic lesions.