Definition

One of the following is true: (1) cancer has spread to one or more lymph nodes on one side of the neck and/or to one or more lymph nodes on one or both sides of the back of the throat. The affected lymph nodes are 6 centimeters or smaller. Cancer is found in the nasopharynx only, or has spread from the nasopharynx to the oropharynx and/or to the nasal cavity, or is found only in the lymph nodes in the neck. The cancer cells in the lymph nodes are infected with Epstein-Barr virus (a virus linked to nasopharyngeal cancer); or (2) cancer has spread to the parapharyngeal space (area near the pharynx, between the base of the skull and the lower jaw) and/or to nearby muscles. Cancer may have also spread to one or more lymph nodes on one side of the neck and/or to one or more lymph nodes on one or both sides of the back of the throat. The affected lymph nodes are 6 centimeters or smaller.