Pathology of the HPV-associated Oropharyngeal Carcinoma

Human papilloma virus (HPV)-associated oropharyngeal carcinoma (HPV-OPC) is increasing in many countries. It has distinct microscopic and molecular features as well as clinical aspects. As for microscopic view, two subtypes, non-keratinizing squamous cell carcinoma (NKSCC) and hybrid SCC (HSCC), 3 variants of SCC, undifferentiated carcinoma (UC), basaloid carcinoma (BC), and papillary squamous cell carcinoma (PSCC), and 2 histological structures, abrupt keratinizarion and comedo-necrosis among non-maturing island are related with HPV-OPC. As for molecular aspects, HPV-OPC is more likely to have p53 degradation and Rb (retinoblastoma protein) inactivation with resulting p16 up-regulation compared to HPV-unassociated oropharyngeal carcinoma.