Severe chromosomal aberrations in pleural mesotheliomas with unusual mesodermal features. Comparative genomic hybridization evidence for a mesothelioma subgroup

Our plain-English summary of Severe chromosomal aberrations in pleural mesotheliomas with unusual mesodermal features. Comparative genomic hybridization evidence for a mesothelioma subgroup, by M. Krismann, K.M. Müller, M. Jaworska, et al (The Journal of Molecular Diagnostics, 2000).

The study

• Authors: M. Krismann, K.M. Müller, M. Jaworska, G. Johnen
• Journal: The Journal of Molecular Diagnostics
• Published: 2000;2(4):209-16
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant mesotheliomas are tumors known for their extensive heterogeneity. Apart from the three classical patterns, predominantly epithelioid, sarcomatoid, and biphasic, some rare variants do exist. In some cases, one can find uncommon additional mesodermal tumor components. These tumors have previously been called "mesodermomas" and, like regular mesotheliomas, are usually associated with a previous asbestos exposure. We examined eight cases of mesodermomas by light microscopy, immunohistochemistry and comparative genomic hybridization (CGH). Besides biphasic and epithelioid areas, unusual epithelial, chondroid, osseous, or even angioblastic elements may be found to varying degrees. Immunohistochemical analysis shows similar staining results as with regular mesotheliomas. CGH reveals a high number of chromosomal imbalances (16.5 per case; range, 11-27). In 10 classical biphasic mesotheliomas that served as a control, defects of comparable number and severity could not be detected (8 per case; range, 2-16). The most frequent defects of mesodermomas (losses on 1p, 4pq, 9p, 13q, 14q, and gains on 1q and 15q), however, could also be found in mesotheliomas of the classical type. Thus, our results support the classification of the so-called mesodermomas as a separate tumor subgroup while maintaining the relationship to the classical mesotheliomas. Therefore, we propose to use the term mesodermoma for this subgroup.

In plain English

This laboratory study from a pathology institute in Bochum, Germany, examined tumor tissue from eight patients with pleural mesothelioma containing unusual tissue elements, such as cartilage-like or bone-like areas. The authors call these tumors "mesodermomas." Six of the eight patients had a known history of asbestos exposure. For comparison, the authors examined 10 classical biphasic mesotheliomas, seven from patients with a history of asbestos exposure. They used antibody staining and comparative genomic hybridization, a method that detects gains and losses of chromosome material. Staining results alone could not tell the two groups apart. The mesodermomas averaged 16.5 chromosome defects per case (range 11 to 27), against 8 per case in the biphasic tumors, only two of which had 11 or more. Several defects, including losses on chromosome arms 1p, 4q and 9p, occurred in both groups. The authors concluded that mesodermomas form a separate subgroup still related to classical mesothelioma. They noted that comparisons could change with more cases and that different areas of one tumor gave somewhat different results.

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: Laboratory pathology study of tumor tissue (immunohistochemistry and comparative genomic hybridization), comparing eight unusual pleural mesotheliomas with a control series of 10 biphasic mesotheliomas
• Who was studied: The study group was eight pleural mesotheliomas (cases M1 to M8; six men and two women, average age 63.1 years) that contained unusual epithelial, chondroid (cartilage-like), osseous (bone-like) or angioblastic elements. The control group was 10 biphasic mesotheliomas (cases B1 to B10, average age 63.1 years). Table 1 lists nine control tumors in the pleura and one in the pericardium. The work was done at the Institute of Pathology, Bergmannsheil Bochum, Germany. Years of diagnosis are not given.
• Exposure: Asbestos exposure history only. Six of eight mesodermoma patients and seven of ten biphasic mesothelioma patients had a known history of asbestos exposure. One mesodermoma patient (M3) is listed as not exposed and one (M6) as unknown. Fiber types and doses were not reported.
• Main results:
  • Mesodermomas had on average 16.5 chromosomal defects per case, ranging from 11 to 27. This was made up of an average of 11.3 losses (range 8 to 15) and 5.2 gains (range zero to 13).
  • The biphasic mesotheliomas (control group) had on average 8 defects per case: 5.4 losses and 2.6 gains.
  • None of the eight mesodermomas had fewer than 11 defects. Only two of the 10 biphasic mesotheliomas had 11 or more.
  • In mesodermomas, losses on chromosome arms 1p, 4q and 9p occurred in all cases (100%). A gain on 15q occurred in 88%.
  • In the biphasic mesotheliomas, the most frequent defects were losses on 22q (70%) and 9p (60%) and gains on chromosome 7 (40 to 50%).
  • Several defects were found in both groups, including losses on 1p, 4p, 4q, 6q, 9p, 13q, 14q and 22q and gains on 1q, 7q and 15q. Losses on 15q were found only in the mesodermoma group.
  • Immunohistochemical staining gave similar results in both groups. The two groups could not be told apart by staining alone.
• The authors' conclusion: The authors concluded that their results support classifying the so-called mesodermomas as a separate tumor subgroup that remains related to classical mesotheliomas. They proposed using the term mesodermoma for this subgroup.
• Limitations the authors state:
  • Differences in where defects were located between the groups may partly reflect the lower number of defects in the biphasic group. These differences could change with more cases.
  • Different areas of the same tumor gave partly different results, reflecting variation within tumors. The authors cautioned against overestimating results obtained from small areas of large tumors.

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, Mesothelioma, Malignant Mesothelioma, Epithelioid, Sarcomatoid, Biphasic Mesothelioma, Asbestos Exposure, Immunohistochemistry.

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• Familial pleural mesothelioma with environmental asbestos exposure: losses of DNA sequences by comparative genomic hybridization (CGH) — G. Serio, A. Scattone, et al. (2004)
• Comparative genomic hybridisation in malignant deciduoid mesothelioma — A. Scattone, A. Pennella, et al. (2006)
• Specificity of asbestos-induced chromosomal aberrations in short-term cultured human mesothelial cells — K. Olofsson, J. Mark (1989)
• Chromosomal aberrations induced by chrysotile and crocidolite in human lymphocytes in vitro — F. Valerio, M. de Ferrari, et al. (1983)

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