Human Papillomavirus-16 Associated Adenocarcinoma NOS of Base of Tongue

The causative role of human papillomavirus (HPV) in a subset of squamous cell carcinomas of the oropharynx (OSCC) is now well established with HPV-16 being detected in approximately 92 % of HPV-positive OSCC in North America. Recently HPV has also been found in some non-squamous oropharyngeal carcinomas including adenosquamous carcinomas, neuroendocrine carcinomas, and undifferentiated "lymphoepithelioma-like" carcinomas. Herein, we report a HPV-16 positive adenocarcinoma NOS arising in the base of the tongue of a non-smoker, 64 year-old male. To our knowledge, this is the first time this association has been clearly documented. The adenocarcinoma was diffusely positive for p16 and HPV-16 was demonstrated by in situ hybridization and linear array analysis. Q-PCR demonstrated a viral load of 4 copies per cancer cell, whereas qRT-PCR for E6/E7 transcript levels were 30 copies per 1,000 human ribosomal protein large P0 (RPLP0) reference gene. The presence of HPV in non-squamous oropharyngeal carcinomas raises the possibility that HPV is also involved in the carcinogenesis of some uncommon carcinomas of the region.