Extranodal extension is a criterion for poor outcome in patients with metastatic nodes from cancer of the nasopharynx

•Extranodal extension (ENE) is an indicator of outcome in nasopharyngeal cancer (NPC).•Advanced ENE infiltrating to adjacent muscle/skin/salivary glands associated with poor outcome in NPC.•Patients with advanced ENE presented similar poor outcome to those with N3 disease.•Study suggested advanced ENE should be included in future staging of NPC. Extranodal extension (ENE) is a criterion for advanced nodal staging of oropharyngeal and hypopharyngeal carcinoma. Our aim was to determine if ENE should be a staging criterion for nasopharyngeal carcinoma (NPC). MRI of 546 NPC patients were reviewed retrospectively and in 404/546 (74.0%) with metastatic nodes, the nodes were assessed for ENE (grade 0 = absent; grade 1 = infiltration of surrounding fat; grade 2 = infiltration of muscle/skin), size (total volume), site (unilateral/bilateral and upper/lower neck) and necrosis. Associations between nodal features and regional relapse free survival (RRFS), distant metastases free survival (DMFS) and overall survival (OS) were assessed using cox regression. Differences of survival rates were compared using log-rank test. A p-value of