Prognostic significance of parapharyngeal space venous plexus and marrow involvement: Potential landmarks of dissemination for stage I-III nasopharyngeal carcinoma

Our findings suggest that the risk of distant metastasis in Stage I-III NPC patients without parapharyngeal space extension or T3 disease is extremely low. Invasion into the parapharyngeal space venous plexus and marrow of the skull base bones is associated with distant metastasis, and involvement of these anatomic sites is considered a potential route for hematogenous disease spread in patients with Stage I-III NPC.