title: [High-resolution CT findings of pulmonary atypical adenomatous hyperplasia of 5 mm or less in diameter].
abstract: OBJECTIVE
  To clarify the high-resolution CT(HRCT) findings of pulmonary atypical adenomatous hyperplasia (AAH) of 5 mm or less in diameter.
  
  
  METHODS
  We evaluated the HRCT findings of 43 histopathologically confirmed AAH of 5 mm or less in diameter in 7 patients who underwent lobectomy for pulmonary adenocarcinoma. For comparison, we also examined the HRCT findings of 13 bronchioloalveolar carcinomas (BAC) of the same size from these patients.
  
  
  RESULTS
  We identified 36 of 43 AAH and all 13 BAC on HRCT performed with multidetector-row CT. Thirty-five AAH and 11 BAC showed ground-glass opacity without any high-attenuation component. Margins of 20 AAH were well defined, and 16 were ill defined. In BAC, 11 lesions demonstrated well-defined margins, with only 2 showing ill-defined margins.
  
  
  CONCLUSIONS
  Most AAH lesions of 5 mm or less in diameter are identified as ground-glass opacity on HRCT. Detection of minute ground-glass opacity is important in locating AAH on HRCT.
authors.affiliation: Division of Radiation Oncology, Division of Cellular and Molecular Pathology, Graduate School of Medical and Dental Science, Niigata University.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Naoya
authors.initials: N
authors.lastname: Koizumi
authors.forename: Makoto
authors.initials: M
authors.lastname: Naito
authors.forename: Hajime
authors.initials: H
authors.lastname: Umezu
authors.forename: Tetsurou
authors.initials: T
authors.lastname: Morita
authors.forename: Takeo
authors.initials: T
authors.lastname: Nemoto
authors.forename: Tomoo
authors.initials: T
authors.lastname: Saito
authors.forename: Mina
authors.initials: M
authors.lastname: Okuizumi
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sasai
mesh_terms: D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000000981:diagnostic imaging* / Q000473:pathology; D018255:Adenomatosis, Pulmonary / Q000000981:diagnostic imaging* / Q000473:pathology*; D000368:Aged; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000000981:diagnostic imaging; D011856:Radiographic Image Enhancement; D014057:Tomography, X-Ray Computed