Environmental Asbestos Exposure as a Possible Pathway to Early-Onset Pleural Mesothelioma: A Case From Afghanistan and Pakistan to London

Our plain-English summary of Environmental Asbestos Exposure as a Possible Pathway to Early-Onset Pleural Mesothelioma: A Case From Afghanistan and Pakistan to London, by S. Mounouchos, A. Aggarwal, A.A. Nafees, et al (Respirology Case Reports, 2026).

The study

• Authors: S. Mounouchos, A. Aggarwal, A.A. Nafees, E. Johnson, P. Cullinan, C. Reynolds
• Journal: Respirology Case Reports
• Published: 2026;14(10):e70774
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant pleural mesothelioma (MPM) is strongly associated with occupational asbestos exposure and typically presents decades after exposure, in older men. The association of MPM with environmental exposure and genetic susceptibility is less recognised. We report a case of a 40-year-old man presenting in London with dyspnoea, weight loss and a persistent right-sided pleural effusion following hospitalisation for pneumonia. Imaging showed circumferential nodular thickening of the right pleura with lymph node involvement, and histopathology was in keeping with epithelioid-type MPM. With no known occupational exposure, childhood residences in Kabul, Afghanistan and Peshawar, Pakistan, where high levels of environmental asbestos are documented, represent plausible sources of environmental exposure. As a result of migration from regions with high environmental asbestos exposure, clinicians in high-income countries may encounter increasing numbers of patients with MPM due to non-occupational asbestos exposure.

© 2026 The Author(s). Respirology Case Reports published by John Wiley & Sons Australia, Ltd on behalf of The Asian Pacific Society of Respirology.

In plain English

This article is a case report about one patient. A 40-year-old man was referred to a respiratory clinic in London with breathlessness and unintentional weight loss after a hospital stay for severe pneumonia. Imaging showed circumferential nodular thickening of the right pleura (the lining around the lung) and enlarged lymph nodes, and the cancer was staged T3N1M0. Fluid drained from around the right lung contained no cancer cells, but a lymph node biopsy showed epithelioid-type malignant mesothelioma. A test for an inherited BAP1 syndrome was negative, and broader genetic testing was not done. The tumour was judged inoperable, and immunotherapy with nivolumab plus ipilimumab was started. He had no known work-related or household asbestos exposure and did not recall living near an asbestos mine. He grew up in Kabul, Afghanistan, and Peshawar, Pakistan, before moving to the UK at 16. The authors concluded that these childhood homes, where environmental asbestos has been documented, were plausible exposure sources, while noting that inherited susceptibility could not be fully excluded.

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 (single patient)
• Who was studied: One 40-year-old man seen in a respiratory outpatient clinic in London. He was born in Kandahar, Afghanistan, moved to Kabul at age 3 and to Peshawar, Pakistan at age 13, and immigrated to the UK at age 16, where he worked as a hospital biochemist. He was an ex-smoker with a five pack-year history.
• Exposure: Suspected childhood environmental (non-occupational) asbestos exposure while living in Kabul, Afghanistan and Peshawar, Pakistan. He had no identifiable occupational or household (para-occupational) asbestos exposure and did not recall living near an asbestos mine. The article reports no fiber type, exposure measurement or fiber analysis for this patient.
• Main results:
  • Imaging showed circumferential nodular thickening of the right pleura with lymph node involvement. FDG-PET showed diffuse pleural uptake, and formal staging was T3N1M0.
  • The right-sided pleural fluid was an exudate (protein 54 g/L, fluid to serum protein ratio 0.72, glucose 3.8 mmol/L, lactate dehydrogenase 490 units/L). Cytology showed lymphocytosis with no malignant cells.
  • Biopsy of an intercostal lymph node showed epithelioid-type malignant mesothelioma with lymphovascular invasion. Tumour cells were positive for calretinin, WT-1 and D2-40 and negative for TTF-1 and adenocarcinoma markers.
  • BAP1 protein expression was retained in the tumour. Germline testing for BAP1 tumour predisposition syndrome was negative, and broader germline panel testing was not performed.
  • The tumour was deemed inoperable, and immunotherapy with nivolumab plus ipilimumab was started.
• The authors' conclusion: The authors concluded that the patient's childhood residences in Kabul and Peshawar, where high levels of environmental asbestos have been documented, were plausible sources of exposure. They noted that the interval between childhood residence and diagnosis at 40 is consistent with recognised mesothelioma latency periods. They stated that clinicians in high-income countries should consider earlier-life environmental and residential exposures acquired overseas, particularly in younger patients without occupational exposure histories.
• Limitations the authors state:
  • The authors stated that inherited susceptibility cannot be fully excluded in this patient, because only BAP1 germline testing was done and BAP1 accounts for only part of known pathogenic germline mutations.

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Pleural Mesothelioma, Environmental Exposure, Pleural Effusion, Pleura, Histopathology, Epithelioid, Occupational Exposure.

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