CT findings in malignant pleural mesothelioma related to nonoccupational exposure to asbestos and fibrous zeolite (erionite)

Our plain-English summary of CT findings in malignant pleural mesothelioma related to nonoccupational exposure to asbestos and fibrous zeolite (erionite), by C. Erzen, M. Eryilmaz, F. Kalyoncu, et al (Journal of Computer Assisted Tomography, 1991).

The study

• Authors: C. Erzen, M. Eryilmaz, F. Kalyoncu, N. Bilir, A. Sahin, Y.I. Baris
• Journal: Journal of Computer Assisted Tomography
• Published: 1991;15(2):256-60
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Endemic malignant pleural mesothelioma (MPM) in Turkey is related to two mineral fibers, tremolite asbestos and fibrous zeolite (erionite). Thirteen cases of MPM from the Cappadocian area, where the soil is rich in erionite, and 29 cases of MPM, from villages whose occupants have high asbestos exposure, were examined by CT. The CT findings of the two groups of MPM were compared with respect to the configuration of the pleural lesions, stage of disease, fissural involvement, pleural effusion, presence of calcified pleural plaques, and chronic fibrosing pleuritis. In erionite-related MPM the pleural lesions were flat and smooth in 69.1%; in asbestos-related MPM the lesions were nodular in 55.1%. Stage IV disease, calcified pleural plaques, and chronic fibrosing pleuritis were more common in the erionite-related MPM. The rest of the findings were similar in both groups. The early radiological diagnosis of erionite-related MPM may be even more difficult because of the similarity of the pleural lesions to chronic fibrosing pleuritis.

In plain English

This study compared computed tomography (CT) chest scans of 42 patients with malignant pleural mesothelioma seen at a university hospital in Ankara, Turkey, between December 1986 and 1988. Thirteen patients came from the Cappadocian villages of Karain and Tuzkoy, which have high nonoccupational exposure to erionite, a fibrous zeolite mineral. The other 29 came from rural areas of Turkey with high asbestos exposure. In the erionite group the pleural lesions were flat and smooth in 69.1%. In the asbestos group they were nodular in 55.1%. The authors reported this difference as statistically significant (chi-square 3.9, p less than 0.05). Stage IV disease was found in 23% of the erionite group and in none of the asbestos group. On the opposite side of the chest, the erionite group showed chronic fibrosing pleuritis in 61.5% and calcified pleural plaques in 38.4%, which the authors reported as significantly more common than in the asbestos group. Fissure involvement, pleural effusion and loss of chest volume were about equally common in both groups. The authors concluded that early radiological diagnosis of erionite-related mesothelioma may be even more difficult because its lesions resemble chronic fibrosing pleuritis.

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: Comparative CT imaging study of two groups of patients with malignant pleural mesothelioma
• Who was studied: 42 patients with malignant pleural mesothelioma given chest CT at Hacettepe University School of Medicine, Ankara, Turkey, between December 1986 and 1988. Thirteen were from the Cappadocian area, from the villages of Karain and Tuzkoy (erionite exposure). The other 29 were from villages in rural areas of Turkey with high asbestos exposure.
• Exposure: Nonoccupational environmental exposure to erionite (fibrous zeolite) in 13 patients and to asbestos in 29 patients. The article names tremolite asbestos and erionite as the two fibers responsible for endemic mesothelioma in Turkey.
• Main results:
  • Erionite-related mesothelioma: pleural lesions were flat and smooth in 69.1%. Asbestos-related mesothelioma: lesions were nodular in 55.1%.
  • Asbestos-related group: in 41.3% the pleura showed diffuse flat pleural thickening with multiple pleural nodules superimposed.
  • Asbestos-related group: single or multiple separate pleural nodules were found in 13.7%.
  • The authors reported the difference in lesion configuration between the groups as statistically significant (chi-square 3.9, p less than 0.05).
  • Stage IV disease was not found in the asbestos group.
  • 23% of the erionite group had Stage IV disease.
  • Bilateral disease was more common in the erionite group (30.7%).
  • In the erionite group, chronic fibrosing pleuritis and calcified pleural plaques were found on the opposite side of the chest in 61.5% and 38.4% respectively.
  • By Fisher's exact test, the authors reported chronic fibrosing pleuritis and calcified pleural plaques as significantly more common in the erionite group (p = 0.00147).
  • Involvement of the pleural fissures, pleural effusion and volume reduction of the involved thorax were found almost equally in both groups.
  • Six erionite-related cases and four asbestos-related cases could not have been diagnosed by CT if other supportive features had been absent.
  • Five patients had a coarse honeycomb pattern of the lung tissue, characteristic of pulmonary fibrosis.
• The authors' conclusion: The authors concluded that, compared with asbestos-related cases, erionite-related mesothelioma more often showed Stage IV disease, flat pleural thickening, calcified pleural plaques and chronic fibrosing pleuritis. They concluded that early radiological diagnosis of erionite-related mesothelioma may be even more difficult because its lesions resemble chronic fibrosing pleuritis.
• Limitations the authors state:
  • Pulmonary fibrosis could not be assessed in all cases because high-quality images were needed, and many Stage III patients could not hold their breath, which degraded image quality.
  • The findings could not be compared with other studies because, to the authors' knowledge, no radiological study of erionite-related mesothelioma had been reported.
  • Distinguishing chronic fibrosing pleuritis due to asbestos or erionite from mesothelioma was not always possible.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Zeolite, erionite, Endemic, Mineral Fiber, Tremolite, Asbestos Exposure, Pleural Effusion.

Related studies

• Malignant pleural mesothelioma caused by environmental exposure to asbestos or erionite in rural Turkey: CT findings in 84 patients — A.A. Sahin, L. Cöplü, et al. (1993)
• Phenotypic characterisation of peripheral blood lymphoid cells in people exposed to fibrous zeolite — M. Ozesmi, A. Karlsson-Parra, et al. (1986)
• Natural fibrous zeolites and their carcinogenicity-a review — K.R. Spurny (1983)
• The in vitro genetic effects of fibrous erionite and crocidolite asbestos — K.T. Kelsey, E. Yano, et al. (1986)
• In vitro genotoxic activities of fibrous erionite — A. Poole, R.C. Brown, et al. (1983)
• Malignant mesothelioma induced by asbestos and zeolite in the mouse peritoneal cavity — Y. Suzuki, N. Kohyama (1984)

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