Widespread pulmonary invasion by malignant pleural mesothelioma: an important diagnostic consideration

Our plain-English summary of Widespread pulmonary invasion by malignant pleural mesothelioma: an important diagnostic consideration, by M. MacMillan, B. Roy, S. McLaren, et al (Respirology Case Reports, 2020).

The study

• Authors: M. MacMillan, B. Roy, S. McLaren, A.K. Nowak, R. Thomas, Y.C.G. Lee
• Journal: Respirology Case Reports
• Published: 2020;8(9):e00675
• Type of article: Case report
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

We report a rare case of early and extensive pulmonary invasion of malignant pleural mesothelioma (MPM) in a 70-year-old woman. She first presented with a hydropneumothorax and subsequent workup, including video-assisted thoracoscopy (VAT), confirmed MPM. After VAT, she developed dyspnoea, cough, and widespread pulmonary infiltrates of uncertain aetiology. These infiltrates progressed over the following months, failed to respond to antibiotics, and were strongly fluorodeoxyglucose (FDG)-avid on positron emission tomography (PET). Bronchoalveolar lavage (BAL) yielded extremely viscous fluid containing mesothelioma cells. These cells were also found in the sputum when nebulized deoxyribonuclease (DNase) was trialled to enhance clearance of the pulmonary fluid. The patient deteriorated rapidly with progressive mediastinal and contralateral MPM involvement and died one month later. This case highlights the importance of including tumour invasion as a differential diagnosis of non-resolving pulmonary infiltrates in patients with MPM.

© 2020 The Authors. Respirology Case Reports published by John Wiley & Sons Australia, Ltd on behalf of The Asian Pacific Society of Respirology.

In plain English

This case report described a previously well 70-year-old woman with malignant pleural mesothelioma. Her cancer spread directly into the lung tissue early in her illness, which the authors called rare. She had domestic exposure to asbestos as a teenager. Lung and pleural biopsy confirmed epithelioid mesothelioma. Six weeks after that procedure, scans showed new hazy changes in her right lung. These worsened over the following months, did not improve with antibiotics, and lit up on PET scanning. A camera examination of her airways (bronchoscopy) found mesothelioma cells in lung fluid and tissue, and the fluid was extremely thick. Mesothelioma cells were also found in her coughed-up sputum after she tried an inhaled medicine (DNase) meant to loosen the secretions, but it gave no clinical benefit. She declined rapidly and was not suitable for cancer drug treatment. She moved to a hospice and died five weeks later. The authors concluded that mesothelioma invasion should be considered when lung changes in mesothelioma patients do not resolve.

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 (a single patient)
• Who was studied: One previously well 70-year-old woman with malignant pleural mesothelioma, reported by authors based in Perth, Western Australia
• Exposure: Domestic (household) asbestos exposure in her teenage years; no fiber type or amount was reported
• Main results:
  • New lung infiltrates appeared in the right middle and lower lobes six weeks after the thoracoscopy biopsy and worsened by four months
  • The lung infiltrates were FDG-avid on PET scanning
  • Bronchoalveolar lavage, bronchial biopsy, and needle aspiration of hilar lymph nodes and lung were positive for malignant mesothelioma, without evidence of infection
  • The lavage fluid was exceedingly viscous and clotted on standing
  • Sputum coughed up during a trial of nebulized DNase contained mesothelioma cells, but DNase did not give a clinical benefit
  • She developed a new pleural effusion on the other side, and 900 mL of chylous fluid was drained
  • Her ECOG performance status fell from 1 to 4 and she was not suitable for systemic therapy. She was transferred to hospice and died five weeks later
• The authors' conclusion: The authors concluded that, although rare, mesothelioma invasion should be included as a possible diagnosis for non-specific lung infiltrates, even in early disease
• Limitations the authors state:
  • The authors stated that how the mesothelioma cells invaded the lung is unknown

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Thoracoscopy, Bronchoalveolar Lavage (BAL), Mesothelioma, Sputum, Differential Diagnosis.

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