Asbestos content of lung tissue in patients with malignant peritoneal mesothelioma: A study of 42 cases

Our plain-English summary of Asbestos content of lung tissue in patients with malignant peritoneal mesothelioma: A study of 42 cases, by G.G. de Ridder, A. Kraynie, E.N. Pavlisko, et al (Ultrastructural Pathology, 2016).

The study

• Authors: G.G. de Ridder, A. Kraynie, E.N. Pavlisko, T.D. Oury, V.L. Roggli
• Journal: Ultrastructural Pathology
• Published: 2016;40(3):134-41
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Lung tissue from 42 peritoneal mesothelioma cases was analyzed by light microscopy and scanning electron microscopy/energy dispersive spectrometry. There were 34 men and 8 women with a mean age of 61 ± 10 years. Also, 17% of cases had histologically confirmed asbestosis, and 26% had only parietal pleural plaques. The asbestos body count exceeded our normal range in 22 of 42 cases (52%). Cases with asbestos-related pulmonary disease had higher fiber burdens than those without. The vast majority of fibers were commercial amphiboles (amosite with lesser amounts of crocidolite). These findings concur with previously published epidemiological observations.

In plain English

This study examined lung tissue from 42 people with malignant peritoneal mesothelioma (mesothelioma of the abdominal lining). They came from 484 such cases in one author's Duke University database, 1982 to 2015. There were 34 men and 8 women. The authors counted asbestos bodies and fibers and identified fiber types by electron microscopy. They formed three groups: asbestosis (Group I, 7); parietal pleural plaques without asbestosis (Group II, 11); and Group III (24): neither condition, or no asbestosis with unknown plaque status (four people). Asbestos levels exceeded the laboratory's normal range in 22 of 42 patients (52%), including only one of the eight women. Median light-microscopy asbestos body counts per gram of wet lung were 159,000 in Group I, 490 in Group II and 4 in Group III. Most fibers were commercial amphiboles, mostly amosite with less crocidolite. Chrysotile was not clearly above background unless those amphiboles were also elevated. Group III was younger and included all the women. The authors considered 6 of its 24 cases asbestos related. They suggested that some peritoneal mesotheliomas are not asbestos related.

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 series: lung tissue fiber analysis (light microscopy and scanning electron microscopy with energy dispersive x-ray analysis) of peritoneal mesothelioma cases drawn from one author's case database
• Who was studied: 42 patients with peritoneal mesothelioma (34 men, 8 women, mean age 61 plus or minus 10 years) whose lung tissue was available. They were drawn from 484 peritoneal mesothelioma cases dated October 1, 1982 to July 22, 2015, in a database at Duke University. Exposure histories came from patient or next-of-kin interviews.
• Exposure: Asbestos measured in lung tissue: asbestos bodies, and uncoated fibers longer than 5 micrometers. Fibers were classed as commercial amphiboles (amosite or crocidolite), noncommercial amphiboles (tremolite, anthophyllite or actinolite), chrysotile, or nonasbestos mineral fibers. Reported exposures included pipe coverers, insulators, shipyard and construction work, and household contact.
• Main results:
  • Patients were grouped as: Group I, asbestosis with or without parietal pleural plaques (n = 7); Group II, plaques without asbestosis (n = 11); Group III (n = 24), patients with neither condition plus four patients without asbestosis whose plaque status was unknown.
  • The four patients with unknown plaque status were placed in Group III because their asbestos body and total fiber values were indistinguishable from those of the other Group III patients.
  • Asbestos levels were elevated in 22 of 42 (52%) of the patients.
  • An elevated tissue asbestos content was found in only one of the eight women.
  • Median asbestos bodies per gram of wet lung by light microscopy: 159,000 in Group I (range 23,000 to 207,000), 490 in Group II (range 14 to 140,000) and 4 in Group III (range 1 to 684,000); P less than 0.05.
  • Median total asbestos fibers (longer than 5 micrometers) per gram of wet lung: 530,000 in Group I, 27,300 in Group II and 1223 in Group III.
  • Any one of the three measures exceeded the normal range in 100% of Group I, 90.9% of Group II and 25% of Group III. The authors compared this with 81.0% for any elevation among 538 pleural mesothelioma cases in their database (from their earlier publications).
  • Most detected fibers were commercial amphiboles, mostly amosite with lesser amounts of crocidolite. Chrysotile was not clearly above background unless commercial amphiboles were also elevated. No case had only noncommercial amphiboles elevated.
  • Groups I and II had no women, while Group III had 8 (35%; P = 0.02). Group III's mean age (55.7 years) was lower than that of Groups I and II (66.6 and 68.4).
• The authors' conclusion: The authors considered 6 of the 24 Group III patients with increased asbestos to be asbestos related. They concluded that the lower mean age and greater proportion of women in Group III suggest that some peritoneal mesotheliomas are not asbestos related and involve other mechanisms.
• Limitations the authors state:
  • Too few cases had noncommercial amphibole or chrysotile levels above background for meaningful analysis of those fiber types.
  • Fiber analysis appeared to have been done more often in sarcomatoid cases than in the full database, for reasons the authors called unclear.
  • Pleural plaque status was unknown for four patients; they were placed in Group III.

Topics

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

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Scanning Electron Microscopy (SEM), Pleural Plaques, Asbestos Body Formation, Fiber Burden, Amphibole Group, Amosite, Crocidolite.

Related studies

• Mineral fiber content of lung tissue in patients with environmental exposures: household contacts vs. building occupants — V.L. Roggli, W.E. Longo (1991)
• Malignant mesothelioma not related to asbestos exposure: Analytical scanning electron microscopic analysis of 83 cases and comparison with 442 asbestos-related cases — A. Kraynie, G.G. de Ridder, et al. (2016)
• Immunohistochemical Evaluation of Minichromosome Maintenance Protein 7 (MCM7), Topoisomerase IIα, and Ki-67 in Diffuse Malignant Peritoneal Mesothelioma Patients Using Tissue Microarray — M. Deraco, A. Cabras, et al. (2015)
• Asbestos content of lung tissue in asbestos associated diseases: a study of 110 cases — V.L. Roggli, P.C. Pratt, et al. (1986)
• Malignant mesothelioma and duration of asbestos exposure: correlation with tissue mineral fibre content — V.L. Roggli (1995)
• Lung dust content in idiopathic pulmonary fibrosis: a study with scanning electron microscopy and energy dispersive x ray analysis — E. Monsó, J.M. Tura, et al. (1991)

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