Incidence of abnormal retropharyngeal lymph nodes in sinonasal malignancies among adults.

INTRODUCTION: The aim of this study is to investigate the relationship between abnormal retropharyngeal lymph nodes (RPLNs) and sinonasal malignancies among adults. METHODS: Magnetic resonance and computed tomography images from 89 patients over 20 years old who were all histopathologically confirmed to have sinonasal malignancies from September 2001 to April 2014 were assessed retrospectively. Abnormal RPLNs were determined as those >5 mm in shortest axis or showing heterogeneous enhancement on axial images. Locations of sinonasal malignancies were categorized using the anterior border of the pterygopalatine fossa as a boundary: (a) anterior lesions, only present anterior to the boundary, or (b) posterior lesions, present or extending posterior to the boundary. Fisher's exact test was used for the analysis of the relationship between frequency of abnormal RPLNs and lesion location. RESULTS: Abnormal RPLNs were present in 13 of 89 patients (15%), including 6 of 41 squamous cell carcinomas (15%), 4 of 24 malignant lymphomas (17%), 3 of 5 olfactory neuroblastomas (60%), and 0 of 19 others (0%). Four of the 39 patients (10%) with anterior lesions showed abnormal RPLNs, compared to 9 of 50 patients (18%) with posterior lesions. No significant difference in frequency of abnormal RPLNs was apparent between anterior and posterior lesions (P = 0.37). CONCLUSIONS: In primary sinonasal malignancies among adults, the highest incidence of abnormal RPLNs was seen with olfactory neuroblastoma. The frequency of abnormal RPLNs was unaffected by the location of sinonasal malignancies among adults.