Katsuya Kato1,2, Kenichi Gemba3,4, Nobukazu Fujimoto3, Keisuke Aoe5, Yukio Takeshima6, Kouki Inai6,7, Takumi Kishimoto8. 1. Department of Radiology, Okayama University Hospital, 2-1-1 Shikatacho, Okayama, 7008558, Japan. kato-rad@med.kawasaki-m.ac.jp. 2. Department of Diagnostic Radiology 2, Kawasaki Medical School, 2-1-80 Nakasange, Kita-ku, Okayama, 7008505, Japan. kato-rad@med.kawasaki-m.ac.jp. 3. Department of Medical Oncology, Okayama Rosai Hospital, 1-10-25 Chikkomidorimachi, Okayama, 7028055, Japan. 4. Department of Respiratory Medicine, Chugoku Chuo Hospital, 148-13 Miyukicho Oaza Kamiiwanari, Fukuyama, 7200001, Japan. 5. Department of Medical Oncology, National Hospital Organization Yamaguchi-Ube Medical Center, 685 Higashikiwa, Ube, 7550241, Japan. 6. Department of Pathology, Hiroshima University Graduate School of Medicine, 1-2-3 Kasumi, Hiroshima, 7340037, Japan. 7. Pathologic Diagnostic Center, Inc., 11-28 Hacchobori, Naka-ku, Hiroshima, 7300013, Japan. 8. Department of Internal Medicine, Okayama Rosai Hospital, 1-10-25 Chikkomidorimachi, Okayama, 7028055, Japan.
Abstract
PURPOSE: The purpose of this study was to clarify the characteristic findings of mesothelioma at the time of diagnosis, and determine precautions and guidelines for diagnosing mesothelioma early in imaging studies. MATERIALS AND METHODS: Overall, 327 patients with pleural mesothelioma were selected from 6030 patients who died of mesothelioma between 2003 and 2008 in Japan. Their imaging findings were examined retrospectively. RESULTS: Plaques were found in 35 % of computed tomography (CT) scans. Asbestosis, diffuse pleural thickening, and rounded atelectasis were found in only seven (2 %), five (2 %), and two cases (1 %), respectively. Pleural thickening findings on CT scans were classified into four stages: no irregularity, mild irregularity, high irregularity, and mass formation. Overall, 18 % of cases did not show a clear irregularity. Localized thickening was observed in the mediastinal (77 %) and basal (76 %) pleura and in the interlobar fissure (49 %). Eight percent of cases did not have any thickening in these three areas. CONCLUSIONS: Upon examination of the CT scans at diagnosis, 18 % of mesothelioma cases did not show a clear irregularity. When diagnosing pleural effusion of unknown etiology, it is necessary to consider the possibility of mesothelioma even when no plaque and pleural irregularity are observed.
PURPOSE: The purpose of this study was to clarify the characteristic findings of mesothelioma at the time of diagnosis, and determine precautions and guidelines for diagnosing mesothelioma early in imaging studies. MATERIALS AND METHODS: Overall, 327 patients with pleural mesothelioma were selected from 6030 patients who died of mesothelioma between 2003 and 2008 in Japan. Their imaging findings were examined retrospectively. RESULTS: Plaques were found in 35 % of computed tomography (CT) scans. Asbestosis, diffuse pleural thickening, and rounded atelectasis were found in only seven (2 %), five (2 %), and two cases (1 %), respectively. Pleural thickening findings on CT scans were classified into four stages: no irregularity, mild irregularity, high irregularity, and mass formation. Overall, 18 % of cases did not show a clear irregularity. Localized thickening was observed in the mediastinal (77 %) and basal (76 %) pleura and in the interlobar fissure (49 %). Eight percent of cases did not have any thickening in these three areas. CONCLUSIONS: Upon examination of the CT scans at diagnosis, 18 % of mesothelioma cases did not show a clear irregularity. When diagnosing pleural effusion of unknown etiology, it is necessary to consider the possibility of mesothelioma even when no plaque and pleural irregularity are observed.
Authors: Martin F Muers; Richard J Stephens; Patricia Fisher; Liz Darlison; Christopher M B Higgs; Erica Lowry; Andrew G Nicholson; Mary O'Brien; Michael Peake; Robin Rudd; Michael Snee; Jeremy Steele; David J Girling; Matthew Nankivell; Cheryl Pugh; Mahesh K B Parmar Journal: Lancet Date: 2008-05-17 Impact factor: 79.321