Human papillomavirus in sinonasal inverted papillomas and squamous cell carcinoma of the larynx. In situ hybridization with human papillomaviruses DNA probes

Background and Purpose: a substantial number of studies have reported evidence on the involvement of human papillomaviruses (HPV) in oral and sinonasal papillomas and carcinomas. Oncogenic HPV subtypes 16 and 18 seem to play an important role in carcinogenesis, whereas low risk HPV subtypes 6 and 11 are usually characteristic of benign lesions. The aim of the present study was to evaluate a role for HPV in the development of sinonasal inverted papillomas and squamous cell carcinomas of the larynx. Materials and Methods: A ten sinonasal inverted papillomas and eight squamous cell carcinomas of the larynx were retrieved from archival material. All examined cases showed histological features of HPV infections (koilocytosis, binucleated squamous cells and abnormal mitoses). All cases have been analyzed using in situ hybridization. A wide spectrum probe for HPV was used initially. Further subtyping was carried out using specific probes for HPV low risk and HPV high risk. Results: Of the ten studied cases of inverted papillomas, one was positive for both: wide spectrum probe and low risk probe, and one was positive for HPV high risk probe only. One of the eight cases of carcinomas was positive for both HPVDNAprobes: wide spectrum probe and high risk probe. Additional positive reactions for HPV DNA using high risk probe were noted in three examined cases of squamous cell carcinomas of the larynx. Conclusions: Our study confirms the role of high risk HPV subtypes in carcinomas. In contrast to other studies, one case only suggests the possible involvement of HPV 6 and HPV 11 in etiology of sinonasal inverted papillomas. The data concerning of the role of HPV in transformation inverted papillomas to squamous cell carcinomas still need further confirmation