Identification of Rare and Common HPV Genotypes in Sinonasal Papillomas.

Sinonasal papillomas are rare, usually benign tumors arising from the Schneiderian membrane. Human papillomaviruses (HPV) can infect differentiating skin and mucosal cells and can induce uncontrolled growth patterns. Their effect on development of sinonasal papillomas has been discussed controversially in recent years. A monocentric, retrospective study was conducted to investigate histopathologic features of sinonasal papillomas and to establish an assay for HPV detection and genotyping in papillomas. Schneiderian papillomas are divided into three groups according to histopathologic features: the largest group are inverted papillomas, followed by fungiform (exophytic) and oncocytic papillomas. HPV screening was performed with high sensitivity by PCR employing My09/11 and 125 consensus primers. Adding a third primer pair (GP5+/GP6+) d increase sensitivity. Reverse hybridization microarrays achieved HPV genotyping better than pyrosequencing in our setting. HPV infection rates were higher in papillomas (46.7%) than infection rates reported for healthy mucosa (up to 13%). P16(INK4a) was not a reliable surrogate marker for HPV infection in sinonasal papillomas. Data from our study endorses the hypothesis that HPV infection promotes formation of sinonasal papillomas. However, apart from HPV genotypes that are frequently found in e.g. anogenital lesions (such as 6, 11, or 16), tissue samples of sinonasal papillomas also displayed infection with "rare" HPV types (such as 58, 42, 83, or 91).