Mesothelial proliferations. An increasing morphologic spectrum

Our plain-English summary of Mesothelial proliferations. An increasing morphologic spectrum, by M.R. Wick, S.E. Mills (American Journal of Clinical Pathology, 2000).

The study

• Authors: M.R. Wick, S.E. Mills
• Journal: American Journal of Clinical Pathology
• Published: 2000;113(5):619-22
• Type of article: Comment, Editorial, Review
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

This editorial accompanied a report in the same journal issue by Khalidi and colleagues describing 3 cases of lymphohistiocytoid (lymphoma-like) malignant mesothelioma, a rare variant first reported in 1988 by Henderson and colleagues from the Australian Mesothelioma Surveillance Program. The authors noted that the incidence of malignant mesothelioma rose sharply through the 1970s and 1980s before reaching a plateau. They reviewed how the classification of mesothelial tumors had been revised over the previous 25 years. Lesions once called benign fibrous mesothelioma were now recognized as solitary fibrous tumor of the pleura, and adenomatoid tumor was now considered mesothelial. The authors preferred to interpret multicystic and well-differentiated papillary mesothelioma as complex hyperplasias. They also described an expanding range of epithelioid, biphasic and sarcomatoid patterns and the tumors each pattern can mimic, including metastatic carcinoma, melanoma, synovial sarcoma and other sarcomas. They discussed the roles of immunohistochemistry, electron microscopy, fluorescence in situ hybridization, polymerase chain reaction and cytogenetics, and stated that testing should be tailored to the tumor's appearance. They argued that separating mesothelioma from its mimics generally did not change treatment or prognosis at the time. In their view, the effort was driven mainly by personal injury litigation, because some mesotheliomas have been linked to amphibole asbestos exposure. They concluded that accurate diagnosis remained worthwhile because future treatments might benefit particular tumor types differently.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This was an editorial that reported no new patient data. The authors wrote it to accompany a report in the same journal issue by Khalidi and colleagues describing 3 cases of a rare mesothelioma variant called lymphohistiocytoid (lymphoma-like) malignant mesothelioma. The authors noted that this variant can closely resemble blood-cell cancers of the pleura. They described how the classification of mesothelial tumors had changed. The lesion once called "benign fibrous mesothelioma" is now considered solitary fibrous tumor of the pleura, an unrelated growth. Malignant mesothelioma now includes many microscopic patterns beyond the traditional epithelioid, biphasic and sarcomatoid types. They wrote that laboratory tests used to confirm the diagnosis should be chosen to fit the tumor's appearance. In the authors' view, separating mesothelioma from look-alike cancers generally did not change treatment or outlook. They wrote that the effort was driven mainly by legal issues, because some mesotheliomas have been linked to aerosolized amphibole asbestos fibers. The authors concluded that pathologists should still aim for the most accurate diagnosis possible, since future treatments may benefit some of these tumors differently.

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: Editorial (opinion and commentary on mesothelial tumor classification and diagnosis); no original data
• Who was studied: No study population. The editorial comments on 3 cases of lymphohistiocytoid mesothelioma reported by Khalidi et al in a separate article in the same journal issue.
• Exposure: Not studied. In discussing why the diagnosis matters in litigation, the authors state, citing earlier work, that some mesotheliomas have been linked pathogenetically with exposure to aerosolized amphibole asbestos fibers.
• Main results:
  • The authors note that lymphohistiocytoid malignant mesothelioma can strikingly resemble malignant hematopoietic (blood-cell) lesions of the pleura, as documented by Henderson and colleagues and by Khalidi and colleagues.
  • According to the authors, the lesion formerly called "benign fibrous mesothelioma" is now known to be solitary fibrous tumor of the pleura, which is unrelated at the cellular and epidemiologic levels.
  • For "multicystic" mesothelioma and "well-differentiated papillary mesothelioma," the authors prefer interpreting them as complex mesothelial hyperplasias, and they state that the clinical outcome is extremely favorable in the vast majority of cases.
  • The authors describe how the epithelioid group of malignant mesothelioma has been expanded to include clear cell, oncocytoid or granular-cell, tubulopapillary, large polygonal cell, mucin-producing, "medullary" and small-cell appearances.
  • The authors state that the laboratory tests used (such as immunostains, electron microscopy, fluorescence in situ hybridization and the polymerase chain reaction) should be tailored to the microscopic appearance of each mesothelioma subtype.
  • In the authors' view, separating malignant mesothelioma from look-alike malignant tumors is generally not critical for treatment or prognosis, because the outlook is equally dismal whether the patient has mesothelioma, metastatic pleural carcinoma or a pleural sarcoma.
  • The authors attribute the effort spent on this distinction primarily to legal issues, noting that some mesotheliomas, but not metastatic carcinomas or pleural sarcomas, have been linked to amphibole asbestos.
• The authors' conclusion: The authors concluded that pathologists should still aspire to the most accurate diagnosis possible in pleural tumors, because future treatments may benefit some of these tumors differently, and that better recognition of the lymphohistiocytoid variant and other forms of mesothelioma furthers that goal.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Lymphohistiocytoid, Malignant Mesothelioma, Mesothelioma, Solitary Fibrous Tumor, Adenomatoid Tumor, Well-Differentiated Papillary Mesothelioma, Epithelioid, Biphasic Mesothelioma.

Related studies

• Mesotheliomas with deciduoid morphology: a morphologic spectrum and a variant not confined to young females — J.H. Shanks, M. Harris, et al. (2000)
• Pathogenesis of pleurisy, pleural fibrosis, and mesothelial proliferation — A. Herbert (1986)
• BAP1 (BRCA1-associated protein 1) is a highly specific marker for differentiating mesothelioma from reactive mesothelial proliferations — M. Cigognetti, S. Lonardi, et al. (2015)
• BAP1 immunohistochemistry and p16 FISH to separate benign from malignant mesothelial proliferations — B.S. Sheffield, H.C. Hwang, et al. (2015)
• New Markers for Separating Benign From Malignant Mesothelial Proliferations: Are We There Yet? — A. Churg, B.S. Sheffield, et al. (2016)
• Oncofetal protein IMP3, a new diagnostic biomarker to distinguish malignant mesothelioma from reactive mesothelial proliferation — M. Shi, A.E. Fraire, et al. (2011)

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