Oropharyngeal cancer is a disease in which malignant cells form in the tissue of oropharynx. The oropharynx is the middle part of the throat that includes the base of the tongue, the tonsils, the soft palate, and the walls of the pharynx.ropharyngeal squamous cell carcinomas [edit]. Oropharyngeal squamous cell carcinomas is a type of head and neck cancer that begins in the oropharynx, the middle part of the throat that includes the soft palate, the base of the tongue, the tonsils, and the side and back wall of the throat.