The pathogenesis of beryllium-induced pulmonary granulomatosis. A scanning secondary ion analytical microscopy study.

Chronic granulomatous pneumonitis was induced in rats with beryllium to study the pathogenesis of that disease, by identifying and localizing the beryllium in histological sections of the pulmonary tissues. This was done with scanning secondary ion mass spectrometry (SIMS). Thus, our observations suggest that the route of the Be from the site of injection into the lung, passes first by the blood, through the vascular wall and into the surrounding pulmonary tissues where Be was phagocytized by macrophages. There resulted in acute vasculitis throughout the lung. It was noted that the granuloma were focal inflammatory sites, solely observed within the vascular wall, distributed along the course of the affected vessel. These findings raise the question as to whether pulmonary granulomatous lesions of other origins are also localized within the vascular wall.