Detailed clinical course of a patient with rapidly progressing sarcomatoid pleural mesothelioma without p16 deletion with systemic haematogenous metastasis to soft tissues

Our plain-English summary of Detailed clinical course of a patient with rapidly progressing sarcomatoid pleural mesothelioma without p16 deletion with systemic haematogenous metastasis to soft tissues, by K. Mizuhashi, K. Okamoto, K. Nabeshima, et al (BMJ Case Reports, 2024).

The study

• Authors: K. Mizuhashi, K. Okamoto, K. Nabeshima, T. Kishimoto
• Journal: BMJ Case Reports
• Published: 2024;17(2)
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Sarcomatoid mesothelioma is difficult to differentiate from other mesotheliomas. Here, we describe the case of a man in his early 80s with sarcomatoid mesothelioma and a history of asbestos exposure. He initially presented with right-sided chest pain and was examined. Right-sided pleural effusion was detected; therefore, he was hospitalised. Based on the observed pleural effusion and biopsy result, the presence of a malignant tumour was excluded; hence, he was diagnosed with benign asbestos pleurisy. He subsequently developed left-sided pleural effusion, masses and lung nodules, and died 9.5 months after the initial examination. A definitive diagnosis of sarcomatoid mesothelioma with rapid systemic progression was established after detailed investigations using autopsy specimens. This rare case of mesothelioma-without p16 deletion (detected using fluorescence in situ hybridisation)-presented differently from the usual sarcomatoid mesothelioma.

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In plain English

This case report described one man in his early 80s who had worked as a carpenter for about 50 years and reported occupational asbestos exposure. The article does not name a fiber type. He first had right-sided chest pain and fluid around the right lung. A CT scan showed a pleural plaque with small calcification but no sign of cancer. Fluid tests and a pleural biopsy indicated a benign condition, and he was diagnosed with work-related benign asbestos pleurisy. Months later, scans showed new nodules in both lungs and disease in the left pleura. A PET scan showed uptake in soft tissues including muscles, tongue, colon, prostate and rectum. He received supportive treatment only and died 9.5 months after his first visit. Autopsy established sarcomatoid pleural mesothelioma, and the earlier biopsy samples showed a similar appearance. Testing found no deletion of the p16 gene, which the authors described as usually detected in this tumour type. The authors concluded that diagnosing sarcomatoid mesothelioma using p16 deletion and BAP1 may not apply to every case.

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 of a single patient, with autopsy and laboratory (immunostaining, PCR and FISH) findings
• Who was studied: one man in his early 80s seen at the authors' hospital for right-sided chest pain
• Exposure: occupational asbestos exposure reported by the patient, who had worked as a carpenter for approximately 50 years; fiber type and dose not given
• Main results:
  • At first presentation, CT showed a right-sided pleural effusion and a pleural plaque with small calcification but no evidence of malignancy
  • A pleural biopsy at another hospital a month later indicated a benign condition
  • Later whole-body PET/CT showed FDG accumulation in the left thoracic wall, ligaments and soft tissues including muscles, tongue, descending colon, right prostate lobe and rectum
  • The patient received supportive treatment only, because the diagnosis was confirmed only at autopsy
  • The patient died 9.5 months after the initial visit, and an autopsy was performed
  • Sarcomatoid mesothelioma was diagnosed from autopsy specimens after other sarcomas were excluded; the earlier pleural biopsy specimens showed a similar histological profile
  • FISH found no homozygous p16 deletion and no hemizygous losses; the authors note such deletion is usually detected in sarcomatoid mesothelioma
  • BAP1 and MTAP expression was mixed, but areas where cells retained expression were more abundant
  • The authors stated the patient survived for 299 days; the article does not say from what point these days were counted
  • The patient was diagnosed with work-related pleural mesothelioma, backdated to the time of the initial visit
• The authors' conclusion: The authors concluded that the current method of diagnosing sarcomatoid mesothelioma using p16 deletion and BAP1 expression may not necessarily apply to all cases
• Limitations the authors state:
  • BAP1 immunohistochemistry was not performed on the pleural fluid
  • BAP1 and MTAP expression in the autopsy specimens was difficult to determine because cells retaining and losing expression were mixed

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Sarcomatoid, Pleural Mesothelioma, Metastasis, Mesothelioma, Asbestos Exposure, Pleural Effusion, Biopsy, Pleurisy.

Related studies

• Deletion status of p16 in effusion smear preparation correlates with that of underlying malignant pleural mesothelioma tissue — T. Hida, S. Matsumoto, et al. (2015)
• Metastasis of Sarcomatoid Malignant Mesothelioma With p16/CDKN2A Deletion Manifested as a Subcutaneous Mass in the Back: A Case Report and Review of Literature — K.B. Chen, Y.J. Huang, et al. (2021)
• Rapidly progressing mesothelioma in an HIV-positive patient — V. Idemyor, C.E. Cherubin (1992)
• Morphological difference between pleural mesothelioma cells in effusion smears with either BAP1 loss or 9p21 homozygous deletion and reactive mesothelial cells without the gene alterations — S. Matsumoto, M. Hamasaki, et al. (2019)
• Clinical Investigation of Benign Asbestos Pleural Effusion — N. Fujimoto, K. Gemba, et al. (2015)
• Benign asbestos pleural effusion: diagnosis and course — B.W. Robinson, A.W. Musk (1981)

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