A Pathological-Radiological Correlation In 108 Cases Of Asbestosis Proven At Post-Mortem

Our plain-English summary of A Pathological-Radiological Correlation In 108 Cases Of Asbestosis Proven At Post-Mortem, by G.K. Sluis-Cremer, J.C. Wagner (1963).

The study

• Authors: G.K. Sluis-Cremer, J.C. Wagner
• Published: Proceedings Of The 14Th International Congress On Occupational Health, Amsterdam: International Congress Series No. 62, Volume Ii, Pp. 608-610 (1963)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 002603. The article is still under copyright, so we describe it here rather than post it.

In plain English

This short congress paper from Johannesburg compared autopsy findings with chest X-rays in 108 cases of asbestosis proved at post-mortem examination. South African law made these examinations obligatory, given permission from next of kin, for people who had worked on controlled mines. All cases with a known work history had worked on crocidolite (blue asbestos) or amosite mines, whose dust also contained free silica. At autopsy, 47 cases were graded slight, 42 moderate and 19 marked asbestosis. On the last available X-ray, asbestosis could have been suspected in only 10 of the 47 slight cases. In 15 of the 42 moderate cases it could not have been suspected, while all marked cases showed signs. Where pulmonary tuberculosis was also present, no slight case could be suspected, and only 10 of 23 moderate cases could be. The authors concluded that a large proportion of slight and nearly a third of moderate asbestosis was not detectable on X-ray. They also concluded that under South African conditions the X-ray features were often atypical, including massive fibrosis, nodulation, pleural changes and frequently asymmetrical signs.

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-based case series comparing the pathological grade of asbestosis found at post-mortem with each person's last chest X-ray (pathological-radiological correlation)
• Who was studied: 108 people in South Africa with asbestosis proved at post-mortem. The examinations were carried out under South African pneumoconiosis legislation, which made post-mortem examination of the heart and lungs obligatory, given permission from next of kin, for people who had worked on controlled mines. At autopsy, 47 cases were graded slight, 42 moderate and 19 marked asbestosis.
• Exposure: Work on crocidolite (blue asbestos) or amosite mines, for all cases with a known industrial history. The ore occurs in banded ironstone containing up to 40% free silica, and mill dust may contain up to 20% free silica. Mill dust counts at the time were about 270 per cc (fibres and particles combined) and underground counts about 160. About 15 years earlier, levels were about 3 times as high.
• Main results:
  • Slight asbestosis: X-ray signs that could raise suspicion were present in only 10 of 47 cases. The authors noted that miniature films were inferior to large films in this group.
  • Moderate asbestosis: 15 of 42 cases could not have been suspected from the X-ray. There was little difference between miniature and large films in this group.
  • Marked asbestosis: all cases (19) could be suspected on either type of film.
  • In cases that also had pulmonary tuberculosis, no case of slight asbestosis could be suspected on X-ray. Only 10 of 23 cases of moderate asbestosis could be suspected; the table shows an alerting abnormality present in 10 and absent in 13.
  • In the 10 slight cases with X-ray signs, the main sign was slight streaky fibrosis at the lung bases, seen in all 10.
  • In the 27 moderate cases with X-ray signs, calcified pleural plaques were seen in 9, and in 2 of these they were the only sign.
  • In marked asbestosis, massive fibrosis (round cannon-ball-like shadows or irregular masses) was seen in 7 cases. None of these showed histological evidence of tuberculosis, though some had lesions consistent with silicotic nodules.
• The authors' conclusion: The authors concluded that a large proportion of cases of slight asbestosis, and nearly a third of cases of moderate asbestosis, are not detectable on X-ray. They also concluded that under South African conditions the X-ray features are often atypical: they include massive fibrosis, P and M nodulation, pleural changes and frequent asymmetry, while the classical basal lesions are relatively infrequent.
• Limitations the authors state:
  • The authors noted that the mine and mill dust in this setting, which contained free silica and iron minerals, differed in important ways from the dust of cleaned and purified asbestos material.
  • The authors stated that the high incidence of tuberculosis in the series does not necessarily indicate a high incidence of tuberculosis in asbestosis. They attributed it probably to three factors: many cases came from tuberculosis hospitals, free silica levels on the mines were high, and many of those affected lived in a low socio-economic environment.
  • The last X-ray was not always close to death: it was taken 1 to 2 years before death in 8 cases, 2 to 3 years in 2 cases, and more than 3 years in 4 cases.

Topics

Medical terms in this study, explained in our Lexicon: Autopsy, Chest X-Ray, Occupational History, Crocidolite, Amosite, Fibrosis.

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