'Black Spots' and hyaline pleural plaques on the parietal pleura of 150 urban necropsy cases

Our plain-English summary of 'Black Spots' and hyaline pleural plaques on the parietal pleura of 150 urban necropsy cases, by K. Mitchev, P. Dumortier, P. De Vuyst (The American Journal of Surgical Pathology, 2002).

The study

• Authors: K. Mitchev, P. Dumortier, P. De Vuyst
• Journal: The American Journal of Surgical Pathology
• Published: 2002;26(9):1198-206
• Cited by: 36 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The absence of any direct connection between the lung and the parietal pleura raises questions about the mechanisms of pleural migration and retention of inhaled particles. It has been suggested that specific areas of parietal pleura absorb and retain inorganic particles from the pleural space, including carbon pigments and asbestos fibers, and could be starting points for pathologic changes induced by mineral fibers. These particle-collecting structures have been called "black spots." To study their distribution, macroscopic appearance, and possible relationship with pleural plaques, the parietal pleura of 150 consecutive necropsies of urban dwellers (mean age 67.7 +/- 12.9 years) were examined. The size and intensity of spots were scored and recorded on a computer scheme together with information of the presence of pleural plaques. Black spots were observed in 92.7% of the cases. They were mainly located in the lower costal and diaphragmatic zones and could correspond to the anatomic distribution of structures involved in pleural cavity clearance. Scores correlated with sex and age. There was no relationship between the predominant locations of black spots and hyaline pleural plaques.

In plain English

This was an autopsy study from the Pathology Department of Erasme Hospital in Brussels, Belgium. The authors examined the parietal pleura (the chest lining on the ribs, diaphragm and mediastinum) in 150 consecutive necropsies of urban dwellers: 96 men and 54 women aged 22 to 93. They looked for 'black spots', which are deposits of dark particles, and for hyaline pleural plaques. They also counted asbestos bodies in lung tissue from 97 cases. Black spots were found in 139 cases (92.7%), mostly in the lower chest wall near the spine and the armpit and on both diaphragms. Spot scores were higher in men than in women and higher in people over 70. Pleural plaques were found in 21 people (14%), 19 of them men. Of 15 cases with more than 1000 asbestos bodies per gram of dry lung, 12 had plaques. Plaques were most common in different places from black spots. No mesothelioma was found. The authors concluded that black spots neither determine nor prevent plaques. The subjects' occupations were not known.

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 (necropsy) study describing consecutive, unselected cases
• Who was studied: 150 consecutive necropsies of urban dwellers at Erasme Hospital, Brussels, Belgium: 96 men and 54 women aged 22 to 93 years (mean 67.7). Study dates are not given.
• Exposure: Asbestos exposure was not directly assessed. The study examined black (anthracotic) spots of particle deposits on the parietal pleura. Asbestos bodies were counted in lung tissue of 97 cases. No information on the subjects' occupations was available, and fiber types were not analyzed in this study.
• Main results:
  • Black spots were present in 139 of 150 cases (92.7%).
  • People with black spots were older on average (68.6 years) than those without (56.3 years); the article reports p less than 0.002.
  • Black spots were most frequent in the lower costal zones. On the right they appeared in the lower paravertebral zone in 84 patients (56%) and the lower axillary zone in 95 (63.3%). On the left the figures were 91 (60.7%) and 97 (64.7%).
  • The total composite black-spot score was higher in men (mean 1.09) than in women (mean 0.79); the article reports a p value of 0.014.
  • Scores were significantly higher in those older than 70 (the article reports a p value of 0.017). Mean scores were 0.69 and 0.93 for groups 1 and 2 (under 60 and 60 to 69), versus 1.00 and 1.39 for groups 3 and 4 (70 to 79 and over 80).
  • Hyaline pleural plaques were found in 21 of 150 subjects (14%): 19 men and 2 women. Plaques were bilateral in 12 and unilateral in 9.
  • Of the 97 cases with lung asbestos body counts, 15 had more than 1000 asbestos bodies per gram of dry lung, and 12 of these 15 (80%) had pleural plaques.
  • Four cases had more than 5000 asbestos bodies per gram of dry lung, and all four had extended bilateral plaques.
  • All plaque cases also had black spots. Mean black-spot scores were 0.94 in those with plaques and 1.25 in those without, a difference that was not statistically significant (the article reports a p value of 0.062).
  • The predominant locations of black spots and pleural plaques did not correlate, although spots and plaques were found very close to each other in 12 cases.
  • No case of pleural mesothelioma was found among the 150 cases.
• The authors' conclusion: The authors concluded that black spots are present in the parietal pleura of the vast majority of the urban population, and that black spots and hyaline pleural plaques develop independently: black spots neither determine nor prevent plaques.
• Limitations the authors state:
  • No information on the subjects' occupations, so work-related causes of black spots could not be interpreted.
  • No mesothelioma cases were found, and thousands of autopsies would be needed to study early mesothelioma. The authors state their observations do not exclude black spots as starting points for malignant mesothelioma.
  • The findings are macroscopic only and need to be completed by microscopic and mineralogical studies.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Pleural Plaques, Parietal Pleura, Autopsy, Mineral Fiber, Pleural Cavity.

Related studies

• Black spots concentrate oncogenic asbestos fibers in the parietal pleura. Thoracoscopic and mineralogic study — C. Boutin, P. Dumortier, et al. (1996)
• Black spots of the parietal pleura: morphology and formal pathogenesis — K.M. Müller, I. Schmitz, et al. (2002)
• Pleural plaques and exposure to mineral fibres in a male urban necropsy population — A. Karjalainen, P.J. Karhunen, et al. (1994)
• Asbestos-related lesions of the pleura: parietal plaques compared to diffuse thickening studied with chest roentgenography, computed tomography, lung function, and gas exchange — G. Hillerdal, P. Malmberg, et al. (1990)
• Chrysotile and tremolite asbestos fibres in the lungs and parietal pleura of Corsican goats — P. Dumortier, F. Rey, et al. (2002)
• Surgical implications of parietal pleural plaques — P.C. Pairolero, P.H. Bernatz, et al. (1973)

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