Spread patterns of retropharyngeal lymph nodal metastasis of nasopharyngeal carcinoma

Abstract

Objective To explore the spread patterns of retropharyngeal lymph node (RLN) metastasis of nasopharyngeal carcinoma. Methods From July 2003 to March 2005, three hundred and three patients with nasopharyngeal carcinoma in initial treatment were enrolled in this study. All patients underwent magnetic resonance imaging (MRI) before treatment, meanwhile measured the minimal and maximal axial diameters, the longitudinal diameter and the central and craniocaudad locations of each positive RLN. Results A total number of 264 positive RLN were found in 177 patients. The minimal and maximal axial diameters and longitudinal diameter of positive RLN were 9.9, 12.9 and 22.4 mm, respectively. Ipsilateral metastatic RLN were noted as follows: two nodes in 21 patients, three nodes in 3 patients and four nodes in 1 patient. According to the longitudinal central location of 263 positive lateral RLN, the numbers of nodes at occipital bone, C1, C1/C2, C2, C2/C3 and C3 were 27, 166, 40, 23, 5 and 2, respectively; the mean minimal axial diameters of nodes were 6.8, 9.9, 12.5, 10.4, 9.3 and 8.0 mm, respectively. Conclusion Multiple metastatic ipsilateral RLN are not common in NPC. The rate of RLN metastasis shows the trend of decreasing from vertebral C1 to C3.The maximal diameters of RLN are in the C1/C2 intervertebral space, and reveal a decreasing frequency along the craniocaudal directions of occipital and vertebral C1. Key words: Nasopharyngeal neoplasms; Diagnosis; Magnetic resonance imaging; Retropharyngeal lymph node; Metastasis