Pleural small cell lung cancer masquerading as malignant mesothelioma: A case report

Our plain-English summary of Pleural small cell lung cancer masquerading as malignant mesothelioma: A case report, by A.H. Hong Lee, S.J. Macalister, K.K. Yap (Radiology Case Reports, 2024).

The study

• Authors: A.H. Hong Lee, S.J. Macalister, K.K. Yap
• Journal: Radiology Case Reports
• Published: 2024;19(8):2969-2972
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Nodular soft tissue pleural thickening on imaging is highly suggestive of malignancy, of which pleural malignant mesothelioma and metastatic disease are differentials. We present the case of a 71-year-old male who presented with acute worsening of shortness of breath associated with a recurrent left pleural effusion post-pleurocentesis. He was an ex-smoker with previous asbestos exposure. Computed tomography performed demonstrated left-sided pleural thickening in the hemithorax and hemidiaphragm with complex pleural effusion. 18F-2-deoxy-d-glucose whole body PET scan revealed extensive uptake throughout the left hemithorax in multiple pleural masses. The imaging findings and clinical case were typical of malignant mesothelioma. However, histopathology results revealed small cell lung cancer. We need to be cognisant of this atypical presentation of a common disease entity. Even when all clinical and imaging findings point towards a certain diagnosis, histopathological assessment cannot be ignored.

© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.

In plain English

This case report described one 71-year-old man transferred to a tertiary hospital with a large left pleural effusion (fluid around the lung) that had come back after it was drained one month earlier. The patient was an ex-smoker with a 12 pack-year history and an ex-factory worker with previous asbestos exposure for 27 years. The article did not name a fiber type. A CT scan showed thickening of the pleura (the lining around the lung) along the left side of the chest and the diaphragm, with a complex effusion. A PET scan showed multiple pleural masses throughout the left side of the chest. Because of this nodular pleural pattern, malignant mesothelioma was the main suspected diagnosis. Pleural samples taken during video-assisted chest surgery instead showed small cell carcinoma, and the tumor cells were not positive for mesothelioma markers. Chemotherapy with palliative intent was suggested for the patient. The authors concluded that histology is always required to confirm the diagnosis, even when the history and imaging look classical for mesothelioma.

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), with a table of earlier published case reports of pleural small cell lung cancer
• Who was studied: One 71-year-old man transferred to a tertiary hospital (the authors are from the Department of Radiology, St Vincent's Hospital Melbourne, Australia) with a recurrent large left pleural effusion
• Exposure: Previous asbestos exposure for 27 years as an ex-factory worker (fiber type not stated); also an ex-smoker with a 12 pack-year history
• Main results:
  • CT showed a nodule and left-sided pleural thickening in the hemithorax and hemidiaphragm with complex pleural effusion, and a 5 mm right upper lobe nodule. Malignant mesothelioma was the main differential diagnosis because of the nodular appearance along the pleural surface.
  • The PET scan showed extensive uptake in multiple pleural masses throughout the left hemithorax. No FDG-avid lymph nodes were seen.
  • The PET scan also showed focally increased uptake in a right lower lobe pleural plaque and the adjacent lung.
  • Pleural tissue showed small cell (neuroendocrine) carcinoma. Tumor cells were positive for CD56 and synaptophysin, negative for TTF-1, and not positive for mesothelioma markers.
  • Based on a diagnosis of extensive small cell lung cancer, chemotherapy with palliative intent was suggested for the patient.
• The authors' conclusion: The authors concluded that although the patient had the classical history and imaging findings of mesothelioma, histology is always required to confirm the diagnosis, and radiological assessment cannot replace histological assessment.

Topics

Medical terms in this study, explained in our Lexicon: Small Cell Lung Cancer, Malignant Mesothelioma, Pleural Thickening, Pleural Effusion, Asbestos Exposure, Hemithorax, PET Scan, Histopathology.

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