title: Narrow band imaging endoscopy for unknown primary tumor sites of the neck.
abstract: BACKGROUND
  Examinations used to search for unknown primary tumors of squamous cell carcinomas of the neck include CT, MRI, laryngoscopy, gastrointestinal endoscopy, and positron-emission tomography (PET). Narrow band imaging (NBI) endoscopy in which an optical color-separation filter is used to narrow the bandwidth of spectral transmittance is also used.
  
  
  METHODS
  Twenty-eight patients in whom primary squamous cell carcinomas could not be detected with conventional white light laryngoscopy underwent NBI endoscopy and PET.
  
  
  RESULTS
  Primary lesions were detected with NBI endoscopy in 3 patients, but no primary lesions were detected with PET. However, PET was used to detect a lower gingival cancer and a palatine tonsillar cancer.
  
  
  CONCLUSIONS
  Both PET and NBI endoscopy is effective for detecting unknown primary tumors of squamous cell carcinomas of the neck.
authors.affiliation: Department of Head and Neck Surgery, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa City, Japan. tashinoz@east.ncc.go.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shinozaki
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Hayashi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ebihara
authors.forename: Masakazu
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Daiko
authors.forename: Masahisa
authors.initials: M
authors.lastname: Saikawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ebihara
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000473:pathology*; D049268:Positron-Emission Tomography; D014741:Video Recording