Malignant mesothelioma mimicking squamous carcinoma in a pleural fluid aspirate

Our plain-English summary of Malignant mesothelioma mimicking squamous carcinoma in a pleural fluid aspirate, by J.S. Johnson, J.M. Edwards (Cytopathology, 2001).

The study

• Authors: J.S. Johnson, J.M. Edwards
• Journal: Cytopathology
• Published: 2001;12(1):54-6
• Type of article: Case report
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This article was a case report from the Department of Histopathology at Blackpool Victoria Hospital in the UK. It described one 63-year-old man, a sheet metal worker who had smoked 30 cigarettes a day for 50 years. He had a 3-month history of shortness of breath, weight loss and cough, and fluid around the right lung. He first denied asbestos exposure, but after diagnosis he reported exposure when cutting through a roof 30 years earlier. Under the microscope, cells in his pleural fluid looked like squamous cell carcinoma, a different cancer. Some cells were described as identical to nonkeratinizing malignant squamous cells. A pleural biopsy instead showed a malignant tumour with no squamous features, and mesothelioma was diagnosed from that biopsy. He died one month after admission. The postmortem examination confirmed a right-sided mesothelioma, found asbestos bodies in the lungs, and found no carcinoma in the lung or elsewhere. The authors concluded that mesothelioma can mimic squamous carcinoma in pleural fluid, a possible diagnostic pitfall, and that this appearance should be recorded to avoid misdiagnosis.

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 63-year-old male smoker (30 cigarettes per day for 50 years), a sheet metal worker, seen at Blackpool Victoria Hospital, UK, with a right-sided pleural effusion
• Exposure: Sheet metal worker who, after diagnosis, reported asbestos exposure when cutting through a roof 30 years earlier; fiber type not stated
• Main results:
  • The pleural fluid contained cells that looked like malignant squamous cells, and no mesothelial cell balls or macronuclei were seen
  • The bronchial brushings and washings were negative
  • The pleural biopsy and autopsy tumour sections showed no squamous differentiation
  • On immunohistochemistry the tumour cells were positive for MNF 116 and CAM 5.2, focally positive for HBME1, and negative for BerEP4, CEA, Leu M1, B72.3 and thrombomodulin; EMA staining was equivocal
  • At postmortem examination: right-sided mesothelioma, asbestos bodies in the lungs, and no carcinoma in the lung or elsewhere
• The authors' conclusion: The authors concluded that mesothelioma can mimic squamous carcinoma in pleural fluid, which creates a diagnostic pitfall. They stated that they were unaware of earlier reports of this and believed it should be recorded to avoid misdiagnosis.

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, Carcinoma, Aspirate.

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• Small orangiophilic squamous-like cells: an underrecognized and useful morphological feature for the diagnosis of malignant mesothelioma in pleural effusion cytology — L. Chen, S.G. Caldero, et al. (2014)
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• Cytomorphological features of metastatic squamous cell carcinoma in serous effusions — C.C. Huang, C.W. Michael (2014)

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