Retropharyngeal lymphadenopathy in nasopharyngeal carcinoma

BACKGROUND: This study was done to investigate the size of normal retropharyngeal lymph nodes (RLN) and the incidence of retropharyngeal lymph node involvement in patients with nasopharyngeal carcinoma (NPC). METHODS: Forty-four NPC patients who had not yet received treatment and 20 control subjects underwent MRI scanning. The number and the maximum diameter of the short axis of the cervical lymph nodes were measured. The number of nasopharyngeal walls involved and the maximum diameter of the tumor were recorded. RESULTS: In 5 of 20 control subjects lateral RLN were identified; none of these nodes was greater than 2.5 mm. In the NPC patients, taking 4 mm as the upper limit of normal RLN, 89% of the patients had enlarged RLN. The number of nasopharyngeal walls involved and the maximum diameter of the primary tumor showed no statistical relationship with the involvement of RLN. There was a statistical association between RLN and level II node involvement, but not with other groups of neck nodes. CONCLUSION: Of all patients with NPC, 89% showed enlarged RLN. Its involvement was related to level II nodes but not to the number of nasopharyngeal sites involved nor with the maximum diameter of the tumor.