A Case of Diffuse Intrapulmonary Malignant Mesothelioma

Our plain-English summary of A Case of Diffuse Intrapulmonary Malignant Mesothelioma, by M. Kumazawa, H. Arakawa, T. Shiobara, et al (Journal of Thoracic Imaging, 2019).

The study

• Authors: M. Kumazawa, H. Arakawa, T. Shiobara, Y. Ishii, Y. Nakazato, Y. Kaji
• Journal: Journal of Thoracic Imaging
• Published: 2019;34(6):W147-W149
• Type of article: Case report
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This article was a case report about one patient in Japan. He was a 69-year-old man, an ex-smoker, who had worked as a dismantling operator and was occupationally exposed to asbestos. The article does not name a fiber type. He had three months of shortness of breath. Imaging showed many small nodules spread through both lungs and a large right pleural effusion (fluid around the lung). The first CT scan showed no pleural mass and no pleural plaques. A later thoracoscopy did find pleural plaque, but no mass. Tuberculosis tests were negative. A pleural biopsy led to a diagnosis of epithelioid malignant pleural mesothelioma. A lung biopsy showed that it had spread into the lung. A second CT on hospital day 41 showed the nodules had merged into ground-glass opacity and consolidation. He was treated with talc pleurodesis and chemotherapy, and he died on day 69 after admission. The authors concluded that this rare form, diffuse intrapulmonary malignant mesothelioma, is a distinct variant of pleural mesothelioma.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (one patient)
• Who was studied: one 69-year-old man, an ex-smoker (42 pack-years), who had worked as a dismantling operator, treated at Dokkyo Medical University School of Medicine, Tochigi, Japan; dates not given
• Exposure: occupational asbestos exposure as a dismantling operator; fiber type, duration and dose not reported
• Main results:
  • The first chest CT showed a right pleural effusion and slight pleural thickening, but no pleural mass and no pleural plaques
  • Tests for tuberculosis were negative
  • At thoracoscopy, pleural plaque was recognized, but there were no mass lesions in the pleural cavity
  • Pleural biopsy and immunostaining led to a diagnosis of epithelioid malignant pleural mesothelioma (MPM)
  • A lung biopsy showed tumor cells with the same staining as the pleural tumor, indicating spread (metastasis) from the pleural mesothelioma to the lung
  • A second CT on the 41st hospital day showed the lung nodules had merged and progressed to ground-glass opacity and consolidation
  • Despite talc pleurodesis and chemotherapy, the patient died on the 69th day after hospitalization
• The authors' conclusion: The authors supposed that the lepidic pattern of spread seen in the lung specimen corresponded to the ground-glass opacity and consolidation on CT. They concluded that, although rare, diffuse intrapulmonary malignant mesothelioma (DIMM) is a unique variant of MPM with characteristic CT and pathologic findings.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma.

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• Diffuse pleural thickening following heart failure-related pleural effusions in an asbestos exposed patient — M. Evison, P. Barber (2015)
• Carcinogenic effect of potassium octatitanate (POT) fibers in the lung and pleura of male Fischer 344 rats after intrapulmonary administration — M. Abdelgied, A.M. El-Gazzar, et al. (2019)
• Role of CT in assessing pleural malignancy prior to thoracoscopy — R.J. Hallifax, M. Haris, et al. (2015)
• Occam's Razor versus Hickam's Dictum — T.A. Newman, J.E. Takasugi, et al. (2017)

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