Malignant pleural mesothelioma in a patient with pneumothorax: A cumbersome subtype both clinically and pathologically

Our plain-English summary of Malignant pleural mesothelioma in a patient with pneumothorax: A cumbersome subtype both clinically and pathologically, by T. Fukui, T. Okubo, N. Tanimoto, et al (Thoracic Cancer, 2021).

The study

• Authors: T. Fukui, T. Okubo, N. Tanimoto, H. Okuma, Y. Shiina, M. Kohama, J. Yamada, Y. Funada, Y. Ikura
• Journal: Thoracic Cancer
• Published: 2021;12(6):974-977
• Type of article: Case report
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Here, we report a case of malignant pleural mesothelioma (MPM) that was very difficult to diagnose. A 62-year-old woman with a surgical history of recurrent bilateral pneumothorax was admitted to our hospital with severe dysphagia. Computed tomography (CT) detected stenosis in the lower esophagus. Immunohistochemical examination of a biopsy sample from the stenotic region was suggestive of MPM. Chemotherapy was initiated, but the patient soon weakened and died. Autopsy revealed atypical cells, identical to those seen in the biopsy sample which had spread into the stenotic esophagus and entire thoracic cavity. Although neither pleural thickening/nodules nor asbestos bodies were observed, we finally diagnosed the tumor as a biphasic-type MPM. We re-examined previous surgical specimens of pneumothorax and acknowledged foci of bland mesothelial cell proliferation which had the same pathological findings as tumor cells at autopsy. The lack of asbestos exposure and pleural thickening, an initial manifestation of pneumothorax, and faint cytological atypia prevented an early diagnosis. In cases of recurrent pneumothorax in elderly patients, MPM should be included in the differential diagnosis.

© 2021 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

In plain English

This case report from Takatsuki General Hospital, Japan, described one patient whose malignant pleural mesothelioma the authors found very hard to diagnose. A 62-year-old woman had undergone surgery for recurrent pneumothorax (collapsed lung) on both sides a year earlier, and no pleural thickening or nodules were seen during surgery. She was later admitted with severe difficulty swallowing. CT showed a narrowed lower esophagus, and a needle biopsy there found atypical cells whose staining suggested mesothelioma. A consulted mesothelioma specialist did not diagnose mesothelioma, but chemotherapy was started. After one course she deteriorated and died. At autopsy there was still no pleural thickening or nodules. Tumor had spread into the esophagus and through the thoracic wall, lungs, heart, stomach and pancreas, and the final diagnosis was biphasic-type mesothelioma. No asbestos bodies were found in the lungs, and the authors stated she had no asbestos exposure. When her earlier pneumothorax specimens were re-examined, they showed mildly atypical mesothelial cells that stained like the tumor. The authors concluded that mesothelioma should be considered in elderly patients with recurrent pneumothorax without emphysema.

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 62-year-old woman admitted to Takatsuki General Hospital, Japan, with severe dysphagia (difficulty swallowing). She had a history, one year earlier, of recurrent bilateral pneumothorax treated surgically each time. Dates of care are not given.
• Exposure: The authors stated the patient had no asbestos exposure, and no asbestos bodies were detected in her lungs at autopsy. No fiber type, product or job is reported.
• Main results:
  • A year before admission the patient had recurrent bilateral pneumothorax, treated surgically each time. Pleural effusion was present, but no pleural thickening or nodules were found during surgery.
  • CT detected narrowing (stenosis) of the lower esophagus. Atypical cells in an EUS-FNA (endoscopic ultrasound-guided fine-needle aspiration) specimen from the narrowed area were positive for calretinin, podoplanin, EMA and CD146, which the authors described as suggestive of MPM.
  • A mesothelioma specialist consulted for a second opinion did not diagnose MPM because characteristic radiological findings were lacking. Chemotherapy (CBDCA+PEM) was started on a potential diagnosis of MPM. After one course, the patient's condition deteriorated and she died.
  • At autopsy, no pleural thickening or nodules were observed, and there was a pleural effusion of 300–400 ml. The final pathological diagnosis was biphasic-type MPM. Tumor cells had spread extensively into the entire thoracic wall, lungs, heart, stomach and pancreas, as well as the strictured lower esophagus.
  • On re-examination of the earlier pneumothorax surgical specimens, nests of proliferating mesothelial cells were found. Their atypia was too mild to distinguish reactive mesothelial hyperplasia from MPM. However, their immunohistochemical findings were identical to those of the autopsy tumor, suggesting the lesions were MPM. Emphysematous change was absent.
• The authors' conclusion: The authors concluded that an early diagnosis was prevented by several factors: the lack of asbestos exposure and of pleural thickening, bilateral pneumothorax as the first manifestation, and faint cytological atypia. They concluded that subclinical MPM should be included in the differential diagnosis of recurrent pneumothorax in elderly patients without emphysematous changes.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Pneumothorax, Bilateral, Dysphagia, Biopsy, Chemotherapy, Autopsy, Pleural Thickening.

Related studies

• Lung function 22-35 years after treatment of idiopathic spontaneous pneumothorax with talc poudrage or simple drainage — P. Lange, J. Mortensen, et al. (1988)
• Spontaneous pneumothorax and pulmonary malignant disease--a syndrome sometimes associated with cavitating tumours. Report of nine new cases, four with metastases and five with primary bronchial tumours — F.W. Wright (1976)
• Intrapleural talc for the prevention of recurrent pneumothorax — J.R. Milanez, F.S. Vargas, et al. (1994)
• Surgically treated pneumothorax. Radiologic and pathologic findings — K.G. Jordan, J.S. Kwong, et al. (1997)
• Pneumothorax and malignant mesothelioma in patients over the age of 40 — J.D. Sheard, W. Taylor, et al. (1991)
• Simultaneous bilateral spontaneous pneumothorax in a patient with peritoneal and pleural papillary mesothelioma — P. Höllinger, D. Gaeng (1997)

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