Patterns of lymph node metastasis from nasopharyngeal carcinoma based on the 2013 updated consensus guidelines for neck node levels

This is the first description of nodal spread patterns based on the updated consensus guidelines. Involvement of the retropharyngeal nodes was mainly located at the lateral group, the medial group was rarely seen. The suggested upper border of level II cannot fully cover all the involved level II nodes. The posterior level V border is not enough to cover all level V lymphadenopathies for NPC.