Asbestos in extrapulmonary sites: omentum and mesentery

Our plain-English summary of Asbestos in extrapulmonary sites: omentum and mesentery, by R.F. Dodson, M.F. O'Sullivan, J. Huang, et al (Chest, 2000).

The study

• Authors: R.F. Dodson, M.F. O'Sullivan, J. Huang, D.B. Holiday, S.P. Hammar
• Journal: Chest
• Published: 2000;117(2):486-93
• Cited by: 50 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Study Objectives: Asbestos fibers have not been reported in tissues from the peritoneal cavity. Therefore, omentum, mesentery, and lung tissues from 20 individuals in whom mesothelioma was diagnosed were analyzed for asbestos bodies and asbestos fibers.

Design: Tissue was digested and prepared filters were analyzed by light microscopy and analytical transmission electron microscopy.

Results: Asbestos bodies were found in the lungs of 18 individuals, mesentery samples from 5, and omentum samples from 2. Uncoated asbestos fibers were found in lungs of 19 patients, 17 of whom had fibers in at least one extrapulmonary site. The most common asbestos in the omentum and mesentery was amosite. Several features of asbestos found in lung influenced the likelihood of amphibole fibers being found in the omentum or mesentery. Lung features included total amphibole fiber burden, length, aspect ratio, and ferruginous body burden. An increased total ferruginous body burden was strongly associated with increased likelihood of detecting amphiboles in the omentum (p < 0. 05).

Conclusion: Asbestos fibers reach areas in the peritoneal cavity where some mesotheliomas develop. This study suggests their presence can be predicted based on concentrations and characteristics of fiber burdens in lung tissue.

In plain English

This study examined autopsy tissue from 20 men with malignant mesothelioma: 17 pleural, 3 peritoneal. Most had worked in jobs with expected asbestos contact, many in shipyards. The authors counted asbestos bodies (coated fibers) by light microscopy and uncoated fibers by electron microscopy in digested lung, omentum and mesentery. Asbestos bodies were found in the lungs of 18 men, the mesentery of 5 and the omentum of 2. Uncoated fibers were found in the lungs of 19 men; 17 also had them in omentum or mesentery. Amosite was the most common type there, in 13 mesentery and 14 omentum samples. Chrysotile was found in 5 mesentery and 3 omentum samples, and crocidolite in 3 and 1. A higher lung asbestos body count was associated with greater likelihood of amphiboles in the omentum (p = 0.0473). No other lung measure reached p less than 0.05, though total amphibole burden, and asbestos body count for the mesentery, approached significance (p less than 0.10). The authors concluded that people with similar exposures and lung burdens would reasonably be expected to have fiber relocation to these sites.

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: Autopsy tissue fiber-burden study (case series of 20 mesothelioma cases), using tissue digestion, light microscopy and analytical transmission electron microscopy, with logistic regression modeling
• Who was studied: 20 men with malignant mesothelioma diagnosed at autopsy by one of the authors, average age 69.8 years. 17 had pleural and 3 (cases 6, 7 and 9) had peritoneal mesothelioma. Dates of death listed in the article's table run from 1990 to 1997. Tissue was analyzed at a laboratory in Tyler, Texas.
• Exposure: Occupational histories, mostly shipyard and related trades such as insulators, pipefitters, boilermakers and machinists. Exposure was assessed through asbestos bodies and uncoated fibers measured in lung, omentum and mesentery, identified by type: chrysotile, amosite, tremolite, crocidolite, anthophyllite and actinolite.
• Main results:
  • Asbestos bodies were found in the lung tissue of 18 of the 20 men (90%).
  • Asbestos bodies were found in the mesentery of 5 men (25%), 2 of whom had peritoneal mesothelioma. They were found in the omentum of 2 men (10%).
  • Uncoated asbestos fibers were found in the lungs of 19 of 20 men (95%). 17 had uncoated fibers in at least one extrapulmonary site (omentum or mesentery).
  • Amosite was the most common asbestos type in the abdominal tissues. It was found in 13 mesentery samples (65%) and 14 omentum samples (70%).
  • Chrysotile was found in 10 lungs (50%), 5 mesentery samples (25%) and 3 omentum samples (15%). Chrysotile reached the omentum and/or mesentery in 25% of cases.
  • Crocidolite was found in 5 lung samples (25%), 3 mesentery samples (15%) and 1 omentum sample (5%).
  • A higher lung asbestos (ferruginous) body count, measured by light microscopy, was associated with a greater likelihood of detecting amphiboles in the omentum (p = 0.0473). The model estimated that above 778 asbestos bodies per gram of dry lung, amphiboles would be found in the omentum in a majority of cases in similar populations.
  • At the authors' marginal threshold (p less than 0.10), total lung amphibole burden approached significance as a predictor of amphiboles in the omentum (p = 0.0866). A burden above 72,515 fibers per gram of dry lung was estimated to give more than a 50% probability of an amphibole fiber in the omentum.
  • For the mesentery, total lung amphibole burden (p = 0.0809) and lung asbestos body count (p = 0.0938) also approached significance. The estimated cutoffs were above 45,801 fibers per gram and above 48.1 asbestos bodies per gram of dry lung.
  • Median lung fiber length and median aspect ratio were not statistically significant predictors. For the omentum, p = 0.1384 and 0.1163; for the mesentery, p = 0.9973 and 0.8266.
• The authors' conclusion: The authors concluded that individuals whose exposure and lung burdens match those of this study population would reasonably be expected to have fibers relocate to the omentum and mesentery. They also stated that chrysotile is translocated and could be potentially important in the development of peritoneal mesothelioma.
• Limitations the authors state:
  • The authors state that the modeled values should be interpreted in terms of the specific sampling procedure used in this study.
  • The authors note that some estimated cutoff values, such as median fiber length for the mesentery, may be unstable because the model is flat.

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: Omentum, Mesentery, Peritoneal Cavity, Mesothelioma, Asbestos Bodies, Analytical Transmission Electron Microscopy (ATEM), Amosite, Amphibole Group.

Related studies

• Asbestos content of omentum and mesentery in nonoccupationally exposed individuals — R.F. Dodson, M.F. O'Sullivan, et al. (2001)
• Neoplastic and inflammatory processes of the peritoneum, omentum, and mesentery: diagnosis with CT — J.E. Hamrick-Turner, M.V. Chiechi, et al. (1992)
• Mesothelial proliferation due to asbestos and man-made fibres. Experimental studies on rat omentum — J. Friemann, K.M. Müller, et al. (1990)
• Combined adenomatoid tumor and well differentiated papillary mesothelioma of the omentum — Y. Hatano, Y. Hirose, et al. (2011)
• Gray scale sonographic presentation of a mesothelioma of the greater omentum — J.M. Shah, D.L. King (1979)
• Primary malignant mesothelioma of the greater omentum: report of a case — Y.C. Liu, Y.L. Kuo, et al. (2004)

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