title: Distinguishing non-Hodgkin lymphoma from squamous cell carcinoma tumors of the head and neck by computed tomography parameters.
abstract: OBJECTIVE
  Computed tomography (CT) remains the first-line imaging procedure for pre-therapeutic staging of head and neck tumors. Non-Hodgkin lymphoma (NHL) is not easily distinguished from squamous cell carcinoma (SCC), especially because NHL often appears in extranodal locations. We sought to explore whether specific CT characteristics could be used to distinguish these tumor types.
  
  
  METHODS
  Cases of NHL and SCC involving the head and neckwere retrospectively identified. Of 165 subjects (110 NHL, 55 SCC) identified, 45 patients (19 NHL, 26 SCC) had complete CT scan records. The scans with no group identifiers were randomly presented to the radiologist for blinded review. Radiologic distribution, size, and tumor characteristics were recorded. Descriptive summaries of the data were analyzed by standard univariate statistical procedures.
  
  
  RESULTS
  Significant differences between NHL and SCC tumors were observed: stage IV tumors (17% vs. 85%; P < .001), extranodal occurrence in the oral cavity (0% vs. 38%; P = .002), evidence of primary or extranodal tumor (11% vs. 73%; P < .001), tumor necrosis (5% vs. 54%; P <.001), non-isodensity nodes (16% vs. 50%; P = .03), and nodes in zones 5-7 (32% vs. 4%; P = .03). No significant difference was seen in the total number of nodes, the number of large nodes, or the maximum nodal diameter.
  
  
  CONCLUSIONS
  While none of these features can be considered pathognomonic for either type of tumor, the distinctions may assist in distinguishing NHL from SCC of the head and neck until more sophisticated imaging techniques become widely available.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Marshfield Clinic, Wisconsin 54449, USA. urquhara@mfldclin.edu
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Urquhart
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Hutchins
authors.forename: Richard L
authors.initials: RL
authors.lastname: Berg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed