title: Nodular ground-glass opacities on thin-section CT: size change during follow-up and pathological results.
abstract: OBJECTIVE
  To evaluate the inter-group differences in growth and the pathological results of nodular ground-glass opacities (GGOs) according to their size and focal solid portions.
  
  
  METHODS
  Ninety-six nodular GGOs in 55 individuals followed by CT for at least one month from an initial chest CT were included. Forty nodular GGOs in 30 individuals were pathologically confirmed to be: adenocarcinoma (n = 15), bronchioloalveolar carcinoma (BAC) (n = 11), atypical adenomatous hyperplasia (AAH) (n = 8), focal interstitial fibrosis (n = 5) and aspergillosis (n = 1). Lesions were categorized based on high-resolution CT findings: pure nodular GGO (PNGGO) < or = 10 mm, PNGGO > 10 mm, mixed nodular GGO (MNGGO) < or = 10 mm, and MNGGO > 10 mm. In each group, the change in size during the follow-up period, the pathological results and the rate of malignancy were evaluated.
  
  
  RESULTS
  Three MNGGO lesions, and none of the PNGGO, grew during the follow-up period. Resected PNGGOs < or = 10 mm were AAH (n = 6), BAC (n = 5), and focal interstitial fibrosis (n = 1). Resected PNGGOs > 10 mm were focal interstitial fibrosis (n = 4), AAH (n = 2), BAC (n = 2), and adenocarcinoma (n = 2). Resected MNGGOs < or = 10 mm were adenocarcinoma (n = 2), and BAC (n = 1). Resected MNGGOs > 10 mm were adenocarcinoma (n = 11), BAC (n = 3), and aspergillosis (n = 1).
  
  
  CONCLUSIONS
  Mixed nodular GGOs (MNGGOs) had the potential for growth; most were pathologically adenocarcinoma or BAC. By contrast, PNGGOs were stable for several months to years; most were AAH, BAC, or focal interstitial fibrosis.
authors.affiliation: Department of Radiology, University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Lee
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Lee
authors.forename: Chul-Gyu
authors.initials: CG
authors.lastname: Yoo
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Jung-Gi
authors.initials: JG
authors.lastname: Im
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*