HPV-Associated Benign Squamous Cell Papillomas in the Upper Aero-Digestive Tract and Their Malignant Potential

Abstract

Squamous cell papilloma (SCP) in the upper aero-digestive tract is a rare disease entity with bimodal age presentation both at childhood and in adults. It originates from stratified squamous and/or respiratory epithelium. Traditionally, SCPs have been linked to chemical or mechanical irritation but, since the 1980s, they have also been associated with human papillomavirus (HPV) infection. Approximately 30% of the head and neck SCPs are associated with HPV infection, with this association being highest for laryngeal papillomas (76-94%), followed by oral (27-48%), sinonasal (25-40%), and oropharyngeal papillomas (6-7%). There is, however, a wide variation in HPV prevalence, the highest being in esophageal SCPs (11-57%). HPV6 and HPV11 are the two main HPV genotypes present, but these are also high-risk HPVs as they are infrequently detected. Some 20% of the oral and oropharyngeal papillomas also contain cutaneous HPV genotypes. Despite their benign morphology, some SCPs tend to recur and even undergo malignant transformation. The highest malignant potential is associated with sinonasal inverted papillomas (7-11%). This review discusses the evidence regarding HPV etiology of benign SCPs in the upper aero-digestive tract and their HPV-related malignant transformation. In addition, studies on HPV exposure at an early age are discussed, as are the animal models shedding light on HPV transmission, viral latency, and its reactivation.

Keywords: aneuploidy; esophagus; human papillomavirus; larynx; malignant transformation; nasopharynx; oral cavity; oropharynx; papilloma; paranasal sinus; risk factor; sinonasal; transmission.

Figure 1

A schematic presentation of the upper aero-digestive tract. This review also includes the more distally located trachea and esophagus. The figure is modified from the original figure published as Figure 3.1, page 16, Report 2/2019, Should boys’ HPV vaccinations be included in the national vaccination programme? the National Institute for Health and Welfare. https://www.julkari.fi/handle/10024/137477, accessed on 23 January 2019. Permission accessed 10 May 2021.

Figure 2

Two different histological types of sinonasal squamous cell papillomas (SNP): (a) sinonasal inverted papilloma (SNIP); (b) sinonasal exophytic papilloma (SNEP).

Figure 3

HPV11-positive oral papilloma of a child.

Figure 4

An endoscopic view of a typical esophageal papilloma (by courtesy of Prof. Matti Eskelinen, University of Eastern Finland, Kuopio).