The diagnosis of desmoplastic malignant mesothelioma

Our plain-English summary of The diagnosis of desmoplastic malignant mesothelioma, by T.V. Colby (American Journal of Clinical Pathology, 1998).

The study

• Author: T.V. Colby
• Journal: American Journal of Clinical Pathology
• Published: 1998;110(2):135-6
• Type of article: Comment, Editorial
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

This editorial commented on a study by Mangano and colleagues, published in the same issue, that proposed histologic criteria for telling desmoplastic malignant mesothelioma (DMM) apart from fibrous pleurisy (FP). The author noted a mesothelioma "epidemic" that was at least partly the result of asbestos exposure in the shipbuilding and construction trades in the 1940s to 1960s, with cases often reviewed as part of asbestos litigation. He stated that DMM made up about 10% of mesotheliomas and that almost all patients died within 18 months. In the study of 31 cases, three observers agreed on the diagnosis in 26 (84%), with a kappa of 0.73. In the other 5 cases, the majority diagnosis matched follow-up. Of the patients with DMM, 23 died of disease and 1 was alive with disease. All 7 patients with FP were alive without disease. DMM was diagnosed in a diffuse fibrosing pleural lesion with storiform or "patternless" areas plus one or more of the following: chest wall or lung invasion (18 cases), bland necrosis (8), frankly sarcomatoid foci (19), or distant metastases (none). The author discussed these features and noted that cytokeratin staining could help in assessing chest wall invasion. He judged underdiagnosis preferable to overdiagnosis and said large specimens were more suitable than closed pleural biopsies. He concluded that the study would likely become the standard for diagnosing DMM.

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 article was a two-page editorial, not an original study. It commented on a separate study by Mangano and colleagues, published in the same journal issue, on telling desmoplastic malignant mesothelioma (DMM) apart from fibrous pleurisy, a benign thickening of the pleura that can look similar under the microscope. As the editorial described it, Mangano et al applied preset microscopic criteria to 31 cases. Three observers agreed on the diagnosis in 26 of 31 cases (84%), with a K statistic (a measure of agreement) of 0.73. In the other 5 cases, the diagnosis that two of the three observers agreed on matched what happened to the patients later. Of the patients diagnosed with DMM, 23 died of disease and 1 was alive with disease. All 7 with fibrous pleurisy were alive without disease. The criteria included invasion of the chest wall or lung, bland necrosis and frankly sarcomatoid areas. The author noted that the definition of sarcomatoid areas left room for variation and that some cases of DMM do not meet the criteria. The author concluded that underdiagnosis is preferable to overdiagnosis, because DMM has no proven therapy.

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 commenting on another study (Mangano et al) published in the same journal issue; no original data
• Who was studied: The author studied no patients. The editorial discusses the series of 31 cases reported by Mangano et al in the same issue.
• Exposure: Not studied. Asbestos exposure in the shipbuilding and construction trades is mentioned only as background, with a citation to another source.
• Main results:
  • As reported in the editorial, three observers in the Mangano et al study agreed on the diagnosis in 26 of 31 cases (84%).
  • In the Mangano et al study the K statistic was 0.73. In the other 5 cases, the diagnosis agreed on by 2 of the 3 observers was consistent with follow-up.
  • In the Mangano et al study, patients with DMM either died of disease (n = 23) or were alive with disease (n = 1).
  • In the Mangano et al study, all patients with fibrous pleurisy were alive without disease (n = 7).
  • In the Mangano et al study, the DMM criteria found in the cases were: invasion of the chest wall or lung in 18 cases, bland necrosis in 8 and frankly sarcomatoid foci in 19. No distant metastases were identified. Four cases fulfilled 3 criteria, 11 fulfilled 2 and 9 fulfilled only 1.
  • According to Mangano et al, as described in the editorial, fibrosis around fat in fibrous pleurisy is cytokeratin negative, whereas invasive DMM shows cytokeratin positivity.
• The authors' conclusion: The author concluded that, because a diagnosis of DMM is a death warrant and the disease has no proven therapy, underdiagnosis is preferable to overdiagnosis.
• Limitations the authors state:
  • The author noted that Mangano et al did not state in how many cases they needed or used cytokeratin staining to assess chest wall invasion.
  • The author noted that identifying frankly sarcomatoid areas varies between observers, and that the authors' definition leaves room for variance.
  • The author noted that cases of DMM that do not fulfill the Mangano et al criteria exist, although they are uncommon.

Topics

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

Medical terms in this study, explained in our Lexicon: Desmoplastic Mesothelioma, Malignant Mesothelioma, Pleurisy, Mesothelioma, Asbestos Exposure, Necrosis, Sarcomatoid.

Related studies

• The diagnosis of desmoplastic malignant mesothelioma and its distinction from fibrous pleurisy: a histologic and immunohistochemical analysis of 31 cases including p53 immunostaining — W.E. Mangano, P.T. Cagle, et al. (1998)
• BAP1 Immunohistochemistry and p16 FISH in the Diagnosis of Sarcomatous and Desmoplastic Mesotheliomas — H.C. Hwang, S. Pyott, et al. (2016)
• The fake fat phenomenon in organizing pleuritis: a source of confusion with desmoplastic malignant mesotheliomas — A. Churg, P. Cagle, et al. (2011)
• Pleuroscopic punch biopsy using insulated-tip diathermic knife-2 for the diagnosis of desmoplastic malignant mesothelioma — K. Masai, S. Sasada, et al. (2013)
• GATA3 Immunohistochemistry for Distinguishing Sarcomatoid and Desmoplastic Mesothelioma From Sarcomatoid Carcinoma of the Lung — K.B. Berg, A. Churg (2017)
• Keratin and epithelial membrane antigen immunoreactivity in nonneoplastic fibrous pleural lesions: implications for the diagnosis of desmoplastic mesothelioma — J.I. Epstein, R.E. Budin (1986)

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