title: Pleural irregularities and mediastinal pleural involvement in early stages of malignant pleural mesothelioma and benign asbestos pleural effusion.
abstract: OBJECTIVE
  To elucidate differences in the level and localization of pleural irregularities in early malignant pleural mesothelioma (eMPM) and benign asbestos pleural effusion (BAPE) using CT.
  
  
  METHODS
  Retrospective assessment of CT findings of consecutive patients with BAPE at a single centre and patients with eMPM reported in Japanese vital statistics.
  
  
  METHODS
  Thirty-six patients with confirmed diagnoses of BAPE and sixty-six patients with confirmed diagnoses of eMPM (mesothelioma stages T1 or T2) were included. Informed consent, CT scans, and clinical and pathologic details were obtained for all patients and were reviewed by one radiologist, two pathologists, and two pulmonologists. Asbestosis, pleural plaque, rounded atelectasis, and diffuse pleural thickening were assessed in all patients.
  
  
  RESULTS
  Prevalence of asbestosis, pleural plaque, rounded atelectasis, and diffuse pleural thickening was significantly higher in the BAPE group. Low-level irregularity was more common in the BAPE group (p<0.001), whereas high-level irregularity, mediastinal localization, and interlobar fissure were more prevalent in the eMPM group (p<0.001). Interlobar pleural irregularity was not observed in any patients in the BAPE group, although 55% of patients in the eMPM group showed interlobar pleural irregularity. Mediastinal pleural involvement was observed in 74% of patients in the eMPM group and had a positive predictive value of 89%.
  
  
  CONCLUSIONS
  This study demonstrates that the level and localization of plural irregularities significantly differed between patients with BAPE and eMPM. Large-scale prospective studies are needed to fully establish the diagnostic utility of such differences.
authors: Department of Radiology, Okayama University Hospital, 2-1-1 Shikatacho, Okayama 7008558, Japan. Electronic address: kato-rad@med.kawasaki-m.ac.jp.
authors: Katsuya
authors: K
authors: Kato
authors: Department of Medical Oncology, Okayama Rosai Hospital, 1-10-25 Chikkomidorimachi, Okayama 7028055, Japan.
authors: Kenichi
authors: K
authors: Gemba
authors: Department of Medical Oncology, Okayama Rosai Hospital, 1-10-25 Chikkomidorimachi, Okayama 7028055, Japan.
authors: Nobukazu
authors: N
authors: Fujimoto
authors: Department of Medical Oncology, National Hospital Organization Yamaguchi-Ube Medical Center, 685 Higashikiwa, Ube 7550241, Japan.
authors: Keisuke
authors: K
authors: Aoe
authors: Department of Pathology, Hiroshima University Graduate School of Medicine, 1-2-3 Kasumi, Hiroshima 7340037, Japan.
authors: Yukio
authors: Y
authors: Takeshima
authors: Department of Pathology, Hiroshima University Graduate School of Medicine, 1-2-3 Kasumi, Hiroshima 7340037, Japan.
authors: Kouki
authors: K
authors: Inai
authors: Department of Internal Medicine, Okayama Rosai Hospital, 1-10-25 Chikkomidorimachi, Okayama 7028055, Japan.
authors: Takumi
authors: T
authors: Kishimoto
mesh_terms: D000368:Aged; D001195:Asbestosis / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D007564:Japan; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008482:Mediastinum / Q000473:pathology*; D008654:Mesothelioma / Q000000981:diagnostic imaging / Q000473:pathology*; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D010994:Pleura / Q000000981:diagnostic imaging / Q000473:pathology*; D010996:Pleural Effusion / Q000000981:diagnostic imaging / Q000473:pathology*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Benign asbestos pleural effusion; CT scan; Mesothelioma