Post-irradiation pericardial malignant mesothelioma with deletion of p16: a case report

Our plain-English summary of Post-irradiation pericardial malignant mesothelioma with deletion of p16: a case report, by Y.B. Naeini, R. Arcega, S. Hirschowitz, et al (Cancer Biology & Medicine, 2018).

The study

• Authors: Y.B. Naeini, R. Arcega, S. Hirschowitz, N. Rao, H. Xu
• Journal: Cancer Biology & Medicine
• Published: 2018;15(1):97-102
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant mesotheliomas are rather uncommon neoplasms associated primarily with asbestos exposure; however, they may also arise as second primary malignancies after radiation therapy, with a latency period of 15-25 years. Numerous studies have reported an association between pleural malignant mesothelioma and chest radiation performed for other malignancies; on the other hand, post-irradiation mesotheliomas of the pericardium have been reported in only a few published cases to date, and no homozygous deletion of 9p21 has been described in such cases. We report the case of a 48-year-old man with a history of Hodgkin's lymphoma and no prior asbestos exposure who developed pericardial malignant epithelioid mesothelioma. We further discuss the cytologic, histologic, immunophenotypic, and fluorescence in situ hybridization findings in this case. To our knowledge, this is the first well-documented case of post-radiation pericardial malignant mesothelioma showing homozygous deletion of 9p21. Homozygous deletion of 9p21, the locus harboring the p16 gene, is present in post-irradiation pericardial malignant mesothelioma.

In plain English

This case report from the pathology department at UCLA described one patient. A 48-year-old man with no history of asbestos exposure developed malignant mesothelioma of the pericardium, the sac around the heart, of the epithelioid type. At age 16 he had been treated for Hodgkin's lymphoma with radiation therapy, lymph node removal and spleen removal. The lymphoma pathology records were not available for review. He had a large fluid collection around the heart. Fluid and tissue samples showed tumor cells carrying markers typical of mesothelial cells. A genetic test (FISH) on 300 nuclei showed extra copies of chromosome 9 and loss of both copies of the 9p21 region, which contains the p16 gene. He developed multiple organ failure and died eight days after diagnosis. The authors argued that the absence of pleural disease weighed against earlier inhaled asbestos exposure. They concluded that, to their knowledge, this was the first case of radiation-induced mesothelioma (their term) showing p16 gene deletion, and that the finding may have potential therapeutic application.

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 48-year-old man with no history of asbestos exposure, seen at the UCLA cardiology unit
• Exposure: Radiation therapy, plus lymph node excision and splenectomy, for Hodgkin's lymphoma at age 16. No asbestos exposure was reported. The article gives no radiation dose or field details.
• Main results:
  • Atypical cells in the pericardial fluid were positive for calretinin and WT1 and negative for MOC31
  • The biopsy was diagnosed as malignant mesothelioma of the epithelioid type. Tumor cells were positive for WT1, CK5/6 and calretinin, and negative for BerEP4, B72.3 and MOC31.
  • FISH, performed on 300 nuclei from marked abnormal regions, showed increased copies of chromosome 9 and homozygous loss of the 9p21 (p16) signals
  • The invasive nature of the tumor, together with the p16 deletion, supported malignant mesothelioma over mesothelial hyperplasia
  • The patient developed multiple organ failure and died eight days after the initial diagnosis
  • The authors argued that the absence of simultaneous pleural disease weighed against previous inhalation exposure to asbestos
• The authors' conclusion: The authors concluded that, to their knowledge, only three post-irradiation pericardial mesotheliomas had previously been reported, and that this was the first case of radiation-induced mesothelioma showing p16 gene deletion. They wrote that the finding may have potential therapeutic application.
• Limitations the authors state:
  • No pathology records of the earlier Hodgkin's lymphoma were available at UCLA for review

Topics

Medical terms in this study, explained in our Lexicon: Pericardial, Mesothelioma, Neoplasm, Asbestos Exposure, Latency, Pericardium, Homozygous Deletion, Epithelioid.

Related studies

• Post-irradiation pericardial malignant mesothelioma: an autopsy case and review of the literature — M. Bendek, M. Ferenc, et al. (2010)
• Changes in surfactant in bronchoalveolar lavage fluid after hemithorax irradiation in patients with mesothelioma — M. Hallman, P. Maasilta, et al. (1990)
• Protocol for PIT: a phase III trial of prophylactic irradiation of tracts in patients with malignant pleural mesothelioma following invasive chest wall intervention — N. Bayman, D. Ardron, et al. (2016)
• Prophylactic irradiation of intervention sites in malignant pleural mesothelioma — M.A. Froment, E. Fréchette, et al. (2011)
• High dose irradiation after pleurectomy/decortication or biopsy for pleural mesothelioma treatment — E. Parisi, A. Romeo, et al. (2017)
• Does selective pleural irradiation of malignant pleural mesothelioma allow radiation dose escalation? : A planning study — A. Botticella, G. Defraene, et al. (2017)

Browse return to medical research.