title: The Pseudocavitation Sign of Lung Adenocarcinoma: A Distinguishing Feature and Imaging Biomarker of Lepidic Growth.
abstract: OBJECTIVE
  Our purpose was to evaluate whether pseudocavitation, characterized by round or oval areas of low attenuation in a lesion on computed tomography (CT), can help distinguish adenocarcinoma from other types of non-small cell lung cancer (NSCLC). We also sought to determine whether pseudocavitation is associated with lepidic growth on histopathology.
  
  
  METHODS
  This retrospective HIPAA-compliant study was approved by our institutional review board. The need for informed consent was waived. CT scans and pathology records from 158 NSCLCs in 149 patients were retrospectively reviewed. The frequency of pseudocavitation was compared among types of NSCLC, specifically adenocarcinoma versus other types of NSCLC. Subgroup analysis of adenocarcinomas was performed to identify any difference in the frequency of pseudocavitation between adenocarcinomas with reported lepidic growth and those without lepidic growth.
  
  
  RESULTS
  There was a significantly greater frequency of pseudocavitation in adenocarcinomas versus other types of NSCLC [19/86 (22.1%) vs. 4/72 (5.6%), P=0.007]. The sensitivity and specificity of the pseudocavitation sign for adenocarcinoma were 0.22 and 0.94, respectively. Among adenocarcinomas, the pseudocavitation sign was more frequent in tumors with lepidic growth versus those without lepidic growth [10/24 (41.7%) vs. 9/62 (14.5%), P=0.015].
  
  
  CONCLUSIONS
  Pseudocavitation at CT is more common in primary lung adenocarcinoma than in other types of NSCLC. It is also more common in adenocarcinomas with lepidic growth, suggesting a correlation between the imaging finding of pseudocavitation and the pathologic finding of lepidic growth. As the subtype of NSCLC guides treatment, predicting tumor pathology by imaging may improve diagnostic workup for patients with NSCLC.
authors.affiliation: Departments of *Radiology †Pathology ‡Medicine, Division of Oncology §Department of Surgery, University of Washington Medical Center, Seattle, WA.
authors.forename: Tina D
authors.initials: TD
authors.lastname: Tailor
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Schmidt
authors.forename: Keith D
authors.initials: KD
authors.lastname: Eaton
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Wood
authors.forename: Sudhakar N J
authors.initials: SN
authors.lastname: Pipavath
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D009367:Neoplasm Staging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D015415:Biomarkers