Mesothelioma Of Pleura Or Peritoneum And Limited Basal Asbestosis

Our plain-English summary of Mesothelioma Of Pleura Or Peritoneum And Limited Basal Asbestosis, by J.G. Thomson (1962).

The study

• Author: J.G. Thomson
• Published: South African Medical Journal 36:759-760, September 8 (1962)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 001586. The article is still under copyright, so we describe it here rather than post it.

In plain English

This short report, an abstract of a paper presented at a research forum, came from the Department of Pathology at the University of Cape Town. The author described 7 cases of mesothelioma found in the autopsy service of one teaching hospital. Three were in the peritoneum and the rest in the pleura. None had asbestosis on clinical or X-ray examination where this was done, and only one patient had a history of working with asbestos. At autopsy the lungs did not look like asbestosis. Careful examination, however, found small scattered spots of scarring in roughly the lowest centimetre of the lower lobes, which were easy to miss. In 6 of the 7 cases these spots showed pulmonary asbestosis with abundant asbestos bodies under the microscope. Sections from elsewhere in the lungs showed no asbestosis. The author also reported this basal asbestosis in 9 patients with mesothelioma examined at 4 centres outside South Africa. The author suggested that gravity and lung movements cause inhaled asbestos fibres to collect at the lung base, reaching a concentration that may cause cancer in the nearby pleura or the peritoneum over the diaphragm. The type of asbestos fibre was not stated.

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 of autopsy findings, published as an abstract of a paper presented at a research forum
• Who was studied: 7 people with mesothelioma seen at autopsy in one teaching hospital, reported by the Department of Pathology, University of Cape Town. One was female, and 3 were described as White. The 7 cases were encountered over 3 years.
• Exposure: Asbestos, fibre type not stated. None of the patients had asbestosis on clinical or X-ray examination where such examination was done. Only one patient had a history of occupational exposure to asbestos.
• Main results:
  • Of the 7 mesotheliomas, 3 were in the peritoneum and the remainder in the pleura.
  • At autopsy, careful examination of all 7 cases found scattered small carbon-pigmented foci of fibrosis in roughly the lowest centimetre of the lower lobes of the lungs. These lesions were inconspicuous and easily overlooked.
  • In 6 of the 7 cases, these basal lesions looked like pulmonary asbestosis with abundant asbestos bodies under the microscope.
  • Sections taken from elsewhere in the lungs showed no asbestosis and usually no asbestos bodies.
  • In one case no asbestos bodies and no basal asbestosis were found, and the author regarded that case as not having the basal asbestosis.
  • The author reported finding basal asbestosis in 9 patients with mesothelioma examined at 4 centres outside South Africa.
• The authors' conclusion: The author suggested that gravity and lung movements cause inhaled asbestos fibres to accumulate at the base of the lung. There, in the author's view, the fibres become asbestos bodies and reach a locally carcinogenic concentration, which acts on the basal pleura or on the peritoneum over the diaphragm a few millimetres away.
• Limitations the authors state:
  • In the one case without basal asbestosis, no smears were taken from the lung base to look for asbestos bodies.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Pleura, Peritoneum, Pathology, Autopsy, Asbestosis, Asbestos Bodies, Diaphragm.

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