Histologic classification and differential diagnosis of mesothelioma

Our plain-English summary of Histologic classification and differential diagnosis of mesothelioma, by D. Carter (The Yale Journal of Biology and Medicine, 1981).

The study

• Author: D. Carter
• Journal: The Yale Journal of Biology and Medicine
• Published: 1981;54(3):173-80
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Free full text

Abstract

Controversy surrounds the diagnosis, classification, and therefore the epidemiology of those tumors which have been designated as mesotheliomas. The group includes lesions which are as broadly different as benign fibrous lesions which some authors refer to as fibromas and anaplastic tumors which are extremely difficult to differentiate from peripheral lung cancers. The former are benign tumors which are usually readily resected and therefore cured. The latter are unresectable tumors which are invariably fatal and which may terminate with extensive metastatic disease. The reasons for including all of these lesions under the category of mesothelioma and the differential diagnosis of the various types is discussed.

In plain English

This was a narrative review by a pathologist, presented at a 1980 symposium on lung tumors. No new patients were studied. The author described how mesotheliomas were classified by cell type under the microscope as spindle cell, epithelial or biphasic (mixed), and by gross appearance as localized or diffuse. According to the author, nearly all biphasic or purely epithelial mesotheliomas were diffuse, malignant and nearly always fatal, while most fibrous spindle cell tumors were benign and localized. The author stated that spindle cell mesotheliomas are not associated with asbestos exposure, while biphasic mesotheliomas have been. The author wrote that telling mesothelioma from reactive pleural tissue rested on cell appearance, invasion and a mass, while stains and electron microscopy mainly helped separate it from carcinoma. The author cited earlier work in which experienced pathologists agreed on diagnosis in only 50 percent of cases. The author stated that ferruginous bodies in lung tissue do not help diagnose mesothelioma. The author concluded that all diagnostic tools, including electron microscopy, should be used much more often to establish the true relationship between asbestos exposure and mesothelioma.

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: Narrative review of the histologic classification and differential diagnosis of mesothelioma, presented at a symposium; no original patient data
• Who was studied: No study population. The article discusses the types of mesothelioma arising in the visceral and parietal pleura, drawing on published literature.
• Exposure: Asbestos exposure in general, discussed from earlier literature. No fiber types are named and no exposure was measured.
• Main results:
  • The author classified mesotheliomas histologically (by microscopic cell type) as spindle, epithelial or biphasic, and grossly as localized or diffuse.
  • According to the author, nearly all biphasic or purely epithelial mesotheliomas were diffuse, malignant and nearly always fatal. Most fibrous spindle cell tumors were histologically benign and localized.
  • The author stated that spindle cell mesotheliomas are not associated with asbestos exposure.
  • The author stated that biphasic mesotheliomas have been associated with asbestos exposure.
  • According to the author, telling mesothelial mesothelioma apart from reactive mesothelium rests on cell appearance, invasion and the presence of a mass lesion.
  • The author described staining for hyaluronic acid as a way to separate mesothelioma from carcinoma: hyaluronic acid in epithelial tumor cells strongly suggests mesothelioma, while staining that persists after hyaluronidase suggests mucus and carcinoma.
  • The author stated that breast and renal cell carcinoma can be very hard to tell apart from reactive mesothelium or mesothelioma by light microscopy, but that this can be done effectively by examining cell ultrastructure.
  • The author described mesothelial cells as having numerous bushy microvilli under electron microscopy, in either reactive or neoplastic mesothelium.
  • The author cited an earlier study (McCaughey and Oldham) in which experienced pathologists agreed on the diagnosis in only 50 percent of cases. This is not a finding of this article.
  • The author stated that ferruginous bodies in lung tissue do not help establish a diagnosis of mesothelioma.
• The authors' conclusion: The author concluded that, because well-documented cases are rare and pathologists do not consistently agree on the diagnosis, all diagnostic tools, including electron microscopy, should be used much more often to reliably establish the epidemiologic relationship between asbestos exposure and mesothelioma.

Topics

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

Medical terms in this study, explained in our Lexicon: Differential Diagnosis, Mesothelioma, Epidemiology, Lung Cancer, Unresectable.

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