Beyond Asbestos: Malignant Pleural Mesothelioma Revealing Lynch Syndrome Through Mismatch Repair Deficiency

Our plain-English summary of Beyond Asbestos: Malignant Pleural Mesothelioma Revealing Lynch Syndrome Through Mismatch Repair Deficiency, by S. Vivanco, S. Vega, A. Muguruza, et al (Curēus, 2026).

The study

• Authors: S. Vivanco, S. Vega, A. Muguruza, A. Garzón, S.D. Zabaleta Orozco, M. Hernández
• Journal: Curēus
• Published: 2026;18(1):e101550
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Lynch syndrome (LS) is a hereditary cancer predisposition condition. We report a rare case of malignant pleural mesothelioma occurring in a patient with this syndrome. The interplay between genetic susceptibility and environmental exposure remains underrecognized. We describe a case of a patient with multiple primary malignancies, including mesothelioma. A 70-year-old woman, with a history of endometrial, breast, and colorectal cancers, developed malignant pleural mesothelioma following 15 years of residence in a mining area with probable asbestos exposure. Immunohistochemistry revealed a loss of PMS2 expression, supporting a defect in MMR. This report documents an exceptional coexistence of malignant pleural mesothelioma and LS, suggesting that impaired DNA repair may lower the carcinogenic threshold for asbestos exposure. Clinicians should consider LS in patients with multiple or atypical malignancies, including mesothelioma, and recommend comprehensive MMR testing and genetic counseling for at-risk relatives.

Copyright © 2026, Vivanco et al.

In plain English

This article is a case report about one patient. A 70-year-old woman had earlier been treated for endometrial cancer (20 years before), right breast cancer (10 years before) and colon cancer (9 years before). Several siblings, a nephew and nieces had colorectal and other cancers. She had lived for 15 years in a mining area in Pasco, Peru, with chronic exposure to dust from blasting. The authors wrote that asbestos exposure was suspected but not directly measured or confirmed, and they named no fiber type. Biopsies taken during thoracoscopic surgery were diagnosed as epithelioid malignant pleural mesothelioma with rhabdoid areas. The tumor was negative for calretinin, a marker the authors noted is usually present. Testing of mismatch repair proteins showed loss of PMS2 only. The authors said this raised strong suspicion of Lynch syndrome, an inherited cancer condition. No outside pathology review was done. She received drainage, chemotherapy, nivolumab and ipilimumab, and no outcome was reported. The authors suggested that defective DNA repair may lower the threshold at which asbestos exposure causes mesothelioma, and called for further studies.

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 70-year-old woman with prior endometrial, right breast and colon cancers and a strong family history of cancer, who had lived in a mining area in Pasco, Peru
• Exposure: 15 years of residence in a mining area with chronic exposure to mining dust from blasting. Asbestos exposure was suspected but not directly measured or confirmed, and no fiber type was specified.
• Main results:
  • Before surgery the patient's only symptom was right-sided chest pain, without shortness of breath
  • During thoracoscopic surgery, tumor spread over the pleura (visceral, parietal, diaphragmatic and pericardial) was seen
  • The pleural tumor was diagnosed as epithelioid malignant mesothelioma with areas of rhabdoid pattern
  • Tumor cells were positive for CK7, WT1 and D2-40, and negative for several other markers, including calretinin
  • Mismatch repair testing showed isolated loss of PMS2, with MLH1, MSH2 and MSH6 preserved
  • The authors described the mismatch repair result as raising strong suspicion for Lynch syndrome
  • The patient was treated with immunotherapy using nivolumab and ipilimumab, after thoracic drainages and chemotherapy
  • Her brother was later diagnosed with colorectal cancer and a cutaneous squamous cell carcinoma, which the authors report were linked to Lynch syndrome
• The authors' conclusion: The authors proposed that defective DNA mismatch repair may lower the carcinogenic threshold, so that even modest or intermittent asbestos exposure could cause mesothelioma in genetically predisposed people. They called for further studies.
• Limitations the authors state:
  • Asbestos exposure was suspected but not directly measured or confirmed
  • No external confirmatory pathology review was performed

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Mismatch Repair Deficiency (dMMR), Environmental Exposure, Mesothelioma, Colorectal Cancer, Asbestos Exposure, Immunohistochemistry, Carcinogenic.

Related studies

• Unusual DNA mismatch repair-deficient tumors in Lynch syndrome: a report of new cases and review of the literature — Y. Karamurzin, Z. Zeng, et al. (2012)
• Mismatch Repair Protein Defects and Microsatellite Instability in Malignant Pleural Mesothelioma — S. Arulananda, B. Thapa, et al. (2018)
• Analysis of mismatch repair (MMR) proteins expression in a series of malignant pleural mesothelioma (MPM) patients — S. Cedrés, S. Ponce-Aix, et al. (2020)
• Metachronous Uterine Endometrioid Adenocarcinoma and Peritoneal Mesothelioma in Lynch Syndrome: A Case Report — Y. Lu, S. Milchgrub, et al. (2017)
• Malignant mesothelioma in Lynch syndrome: A report of two cases and a review of the literature — A.R. Shih, R.L. Kradin (2019)
• Primary Peritoneal Low-grade Serous Carcinoma in a Patient With Lynch Syndrome: A Case Report — S. Makiuchi, H. Yoshida, et al. (2020)

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