Pneumatosis Pulmonalis

Our plain-English summary of Pneumatosis Pulmonalis, by L.L. Brewer, P.S. Moskowitz, C.B. Carrington, et al (1979).

The study

• Authors: L.L. Brewer, P.S. Moskowitz, C.B. Carrington, K.G. Bensch
• Published: American Journal of Pathology, Volume 95 No1. April 1979
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This Stanford University case series concerns a lung complication in newborns, not asbestos. The authors described five premature infants, born at 26 to 32 weeks of gestation, who were treated with mechanical ventilation for the idiopathic respiratory distress syndrome. All five developed persistent air trapped in lung tissue (pulmonary interstitial emphysema) within the first 3 days of life. Its observed duration was 12 to 21 days. It was still present when three infants (Cases 3, 4 and 5) died, and the other two (Cases 1 and 2) survived after the affected lobe was removed. Tension pneumothorax (collapsed lung under pressure) recurred in all the infants. Removed lobes and autopsy lungs contained air-filled cysts up to 0.8 cm across. Under the light microscope, the cysts were usually lined by plump cells and multinucleated giant cells. Electron microscopy of tissue from Cases 1, 2 and 3, which was suboptimally preserved, showed lining cells with connective tissue features and no epithelial cells in the cysts. The authors concluded that this persistent form is a distinct entity resembling pneumatosis intestinalis of the bowel, and they proposed calling it pneumatosis.

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 (five case reports) with radiographic, gross, light microscopic and electron microscopic pathology findings
• Who was studied: five premature neonates (born at 26 to 32 weeks of gestation) with idiopathic respiratory distress syndrome treated at Stanford University hospital; the article gives no study dates
• Exposure: mechanical (positive pressure) ventilation and supplemental oxygen for idiopathic respiratory distress syndrome; asbestos was not studied
• Main results:
  • In all five infants, pulmonary interstitial emphysema developed within the first 3 days of life and was usually bilateral
  • The observed duration of pulmonary interstitial emphysema was 12 to 21 days. This period ended with death while it was still present in three infants, and with lobectomy in the other two. It did not end in resolution.
  • Tension pneumothorax recurred in all five infants
  • Three infants died (Case 3 at 5 weeks of age, Case 5 on day 19, Case 4 on day 21)
  • Of the two survivors (Cases 1 and 2, both after lobectomy), later radiographs showed bronchopulmonary dysplasia in one and normal lungs in the other
  • On gross examination, the lobectomy specimens of Cases 1 and 2 contained thin-walled cysts measuring 0.1 to 0.8 cm
  • No bronchial or vascular abnormalities were found in any case
  • Under the light microscope, the cysts were usually lined by plump cells resembling macrophages and by multinucleated giant cells
  • Electron microscopy, done on tissue from Cases 1, 2 and 3 only, showed that the cyst lining cells had the characteristics of mesenchymal (connective tissue) cells, and that the cysts never contained epithelial cells
• The authors' conclusion: The authors concluded that persistent interstitial pulmonary emphysema is a distinct histopathologic entity. Because its microscopic features resemble pneumatosis intestinalis, they applied the term 'pneumatosis' to it. They also concluded that persistent gas pockets in connective tissue prompt mesenchymal cells to try to wall them off.
• Limitations the authors state:
  • Preservation of the tissue for electron microscopy was suboptimal

Topics

Medical terms in this study, explained in our Lexicon: Pneumatosis Pulmonalis, Idiopathic, Interstitial, Emphysema, Pneumothorax, Autopsy.

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