Human papillomavirus: cause of epithelial lacrimal sac neoplasia?

Epithelial tumours of the lacrimal sac are rare but important entities that may carry grave prognoses. In this study the prevalence and possible role of human papillomavirus (HPV) infection in epithelial tumours of the lacrimal sac were evaluated.

Five papillomas and six carcinomas of the lacrimal sac were investigated for the presence of HPV using the polymerase chain reaction (PCR) technique. Fifteen specimens of dacryocystitis were included in the PCR reactions as controls. Furthermore, DNA in situ hybridization (ISH) and RNA ISH were performed.

Low-risk HPV types 6 or 11 were identified in all four lacrimal sac papillomas suitable for PCR analysis and in situ hybridization. Four of six lacrimal sac carcinomas harboured HPV. One carcinoma was positive for HPV 11 only, two carcinomas had concomitant infection with HPV 6 or 11 and high-risk HPV 16, and the remaining carcinoma was positive for HPV 16. All specimens of dacryocystitis were betaglobin-positive and HPV-negative. Using DNA ISH, two papillomas and a single carcinoma showed evidence for vegetative HPV 11 DNA replication, whereas no HPV 16 DNA replication was found in the five carcinomas tested. HPV 11 RNA was demonstrated in two papillomas.

By analysing 11 epithelial lacrimal sac papillomas and carcinomas using PCR, DNA ISH and RNA ISH, we found HPV DNA in all investigated transitional epithelium tumours of the lacrimal sac. HPV RNA was present in two of eight epithelial lacrimal sac tumours positive for HPV DNA. As RNA degrades fast in paraffin-embedded tissue, only a small fraction of DNA-positive tumours can be expected to be RNA-positive. We therefore suggest that HPV infection is associated with the development of lacrimal sac papillomas and carcinomas.