title: Incidence of abnormal retropharyngeal lymph nodes in sinonasal malignancies among adults.
abstract: BACKGROUND
  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.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan, m2076193@med.osaka-cu.ac.jp.
authors.forename: Asari
authors.initials: A
authors.lastname: Sai
authors.forename: Taro
authors.initials: T
authors.lastname: Shimono
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Toru
authors.initials: T
authors.lastname: Takeshita
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ohsawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Wakasa
authors.forename: Yukio
authors.initials: Y
authors.lastname: Miki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015994:Incidence; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009669:Nose Neoplasms / Q000473:pathology*; D010256:Paranasal Sinuses; D010614:Pharynx; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed