Computed tomographic findings of environmental asbestos-related malignant pleural mesothelioma

Our plain-English summary of Computed tomographic findings of environmental asbestos-related malignant pleural mesothelioma, by U.M. Yilmaz, G. Utkaner, E. Yalniz, et al (Respirology, 1998).

The study

• Authors: U.M. Yilmaz, G. Utkaner, E. Yalniz, Z. Kumcuoglu
• Journal: Respirology
• Published: 1998;3(1):33-8
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Malignant pleural mesothelioma (MPM) is not an infrequent fatal neoplasm. It is endemically present in some regions of Turkey due to its aetiological relationship to exposure to environmental fibrous minerals. The aim of this study was to determine the thorax computed tomographic (CT) features of environmental asbestos-related MPM. In this study, we examined retrospectively the CT scans of 46 untreated patients with pathological diagnosis of environmental asbestos-related MPM among 151 patients with malignant pleural mesothelioma in the Izmir Chest Disease and Surgery Hospital. The CT scans were interpreted by consultation of four observers. Malignant pleural mesothelioma was unilateral in 45 (97.2%) of the patients. Pleural effusions were found in 42 (91%) of the patients, pleural calcifications in 12 (26%), contracted hemithorax in 14 (30%), interlobar fissure involvement in 25 (54%) and mediastinal pleural involvement in 26 (57%). A contracted hemithorax was significantly correlated with pleural rind configuration. Pleural thickenings were found in 45 (99%) of the patients. Pleural thickenings were in the form of nodularity in 10 (22%) cases, regular in 12 (27%) cases, as a focal mass in 3 (7%) cases and as a pleural rind in 20 (44%) cases. Pleural thickening was greater than 1 cm in 32 (71%) cases. The most common CT findings in our series were unilateral circumferential pleural thickening, nodular pleural thickening, pleural thickening greater than 1 cm and mediastinal pleural involvement. Generally, pleural effusion was accompanied by this. There was interlobar fissure involvement in half of the patients. There was no pathognomonic CT finding in environmental asbestos-related MPM. But CT was useful in suggesting the diagnosis of malignant pleural disease in the cases with MPM.

In plain English

This study looked back at chest CT scans from people in Turkey with malignant pleural mesothelioma that the authors attributed to environmental (non-occupational) asbestos exposure. Of 151 patients diagnosed with this cancer at the Izmir Chest Disease and Surgery Hospital between 1990 and 1996, 46 had CT scans before any treatment. Patients with occupational asbestos exposure were excluded. Four observers interpreted the scans together. The tumour was on one side of the chest in 45 patients (30 right, 15 left) and on both sides in one. Pleural thickening was seen in 45 patients. It was nodular in 10 (22%), regular in 12 (27%), a focal mass in 3 (7%) and a rind encasing the lung in 20 (44%). Thickening was greater than 1 cm in 32 (71%). Pleural effusions (fluid) were present in 42 of the 46 patients. The interlobar fissures were involved in 25 (54%) and the mediastinal pleura in 26 (57%). The authors concluded that no CT finding was pathognomonic, meaning unique to this disease, but that CT was useful in suggesting malignant pleural disease.

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: Retrospective review of CT scans (case series) from one hospital, interpreted by four observers who reached a consensus
• Who was studied: 46 patients with pathologically proven malignant pleural mesothelioma who had chest CT before treatment, selected from 151 patients diagnosed with this disease in 1990–1996 at the Izmir Chest Disease and Surgery Hospital, a regional referral centre in Turkey. Patients from Cappadocia and immigrants born abroad were also excluded. The male/female ratio was 35/11.
• Exposure: Environmental (non-occupational) asbestos exposure, judged from patients' recorded occupational and lifestyle histories. Patients with occupational asbestos exposure were excluded. The article does not report fiber type or exposure source for individual patients. Its introduction describes tremolite-contaminated white stucco as a source in rural Turkey in general.
• Main results:
  • Mesothelioma was on one side of the chest in 45 of 46 patients (Table 1 gives 97.8%; the abstract prints 97.2%): the right side in 30 and the left in 15. It was on both sides in 1 patient (2.2%).
  • Pleural lesions were seen more often in the lower half than in the upper half of the chest (30 vs 15).
  • Pleural thickening was found in 45 patients, printed as 99%.
  • Patterns of pleural thickening: nodular in 10 (22%), regular in 12 (27%), focal mass in 3 (7%), pleural rind in 20 (44%).
  • Pleural thickening was greater than 1 cm in 32 (71%) cases.
  • Pleural effusions were present in 42 of the 46 patients (printed as 90% in the results and 91% in the abstract and Table 4).
  • Effusions were massive (more than half of the chest side) in 18 patients.
  • The interlobar fissures were involved in 25 (54%) patients.
  • The mediastinal pleura was involved in 26 (57%) patients.
  • Pleural calcification on the same side as the tumour was seen in 12 (26%) patients. In six of these, the calcification was in calcified pleural plaques.
  • The affected side of the chest was contracted in 14 (30%) patients. The authors stated that a contracted hemithorax was significantly correlated with the pleural rind pattern.
  • Mediastinal lymph node enlargement was seen in 6 patients (13%).
  • Chest wall involvement was seen in 5 patients (11%).
• The authors' conclusion: The authors concluded that there was no CT finding unique (pathognomonic) to environmental asbestos-related malignant pleural mesothelioma, but that CT was useful in suggesting malignant pleural disease in these patients.
• Limitations the authors state:
  • Assessing invasion of the pericardium was difficult because the neighbouring mediastinal pleura was also involved.
  • In some patients with calcification on the tumour side, CT could not distinguish benign pleural plaque from mesothelioma.

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, Neoplasm, Thorax, CT Scan, Pleural Effusion, Pleural Calcification, Hemithorax, Fissure Involvement.

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