Adenosquamous carcinoma of the head and neck: relationship to human papillomavirus and review of the literature.

Adenosquamous carcinoma (ADSC) of the head and neck is an aggressive variant of squamous cell carcinoma (SCC). Certain variants of head and neck SCC are human papillomavirus (HPV)-related and have better prognosis. The relationship of HPV to head and neck ADSC has not been investigated. We searched our files for the term "adenosquamous" and head and neck subsites and found cases from 1998 to 2009. The requisite histologic criteria were the presence of SCC combined with distinct gland formation and/or intracellular mucin. DNA in situ hybridization for high-risk HPV, RNA in situ hybridization for high risk HPV E6 and E7 transcripts, and immunohistochemistry for p16 and p53 were performed. The existing literature on ADSC was also reviewed. Of the 18 cases, eight were from the larynx and hypopharynx, four from the oral cavity, three from the oropharynx, and three from the nasal cavity. Three cases (16%) showed both high risk HPV E6 and E7 and p16 expression, one from the nasal cavity and two from the oropharynx. Both oropharyngeal carcinoma patients were alive and disease free at 34 and 103 months, respectively. ADSCs of the head and neck are a heterogeneous group of tumors. A small minority of cases harbor HPV and most of these, particularly those occurring at sites with known high prevalence of HPV, show active viral transcription with detectable E6 and E7 and overexpression of p16. The HPV-related oropharyngeal cases, though rare, appear to do very well clinically, while the remaining cohort of ADSC patients do quite poorly. Head and neck ADSC appears to be a mixed variant that can be further classified according to its HPV status.