title: HRCT features of small peripheral lung carcinomas detected in a low-dose CT screening program.
abstract: OBJECTIVE
  To define high-resolution computed tomography (HRCT) features of lung cancers detected by computed tomography (CT) screening according to histopathology and prognosis.
  
  
  METHODS
  Tumor size, CT value, morphology, and tumor volume doubling time (TVDT) were determined for 10 atypical adenomatous hyperplasias (AAH) and 50 lung cancers followed between 1996 and 1998 to 2007.
  
  
  RESULTS
  For the 10 AAHs, the density less than -500 HU in all lesions (mean, -654 HU) and the size was up to 14 mm (mean, 9 mm); all patients remain alive. Focal bronchioloalveolar cell carcinomas (BAC) were denser (mean, -537 HU) than AAH and mostly less dense than -350 HU; all patients remain alive. All 22 adenocarcinomas (ADC) were denser than -450 HU (mean, -186 HU); 6 were problematic and measured >-150HU and >10 mm or had >10 mm of central denser zone (CDZ) (partly solid tumors) or tumor size (solid tumor). Two of four squamous cell carcinomas (SCC) measuring 15 and 10 mm, respectively, were problematic. Two patients with small-cell lung carcinomas (SCLC) measuring 15 and 23 mm, respectively, remain alive. AAH, BAC, ADC, and SCC lesions were in general polygonal in shape. SCLC lesions appeared as round nodules with excrescence. The mean TVDT for AAH, BAC, ADC, SCC, and SCLC was 1278, 557, 466, 212, and 103 days, respectively.
  
  
  CONCLUSIONS
  The CT features reflected tumor aggressiveness. Non-SCLC lesions of >-150HU and >10 mm (or >-100HU and >10 mm for the solid portion of the tumor) are associated with unfavorable prognosis. Timely interventions should be undertaken before problematic increase in number of cases.
authors.affiliation: JA Nagano Azumi General Hospital, Ikeda, Nagano, Japan. shu_sones_37@ybb.ne.jp
authors.forename: Shusuke
authors.initials: S
authors.lastname: Sone
authors.forename: Toru
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Honda
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsushima
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Takayama
authors.forename: Takaomi
authors.initials: T
authors.lastname: Hanaoka
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Kondo
authors.forename: Masayuki
authors.initials: M
authors.lastname: Haniuda
mesh_terms: D000368:Aged; D001822:Body Burden; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*