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

Chronic granulomatous pneumonitis was induced in rats with beryllium to stu dy the pathogenesis of that disease, by identifying and localizing the bery llium in histological sections of the pulmonary tissues. This was done with scanning secondary ion mass spectrometry (SIMS). Thus, our observations su ggest that the route of the Be from the site of injection into the lung, pa sses first by the blood, th rough the vascular wall and into the surroundin g pulmonary tissues where Be was phagocytized by macrophages. There resulte d in acute vasculitis throughout the lung. It was noted that the granuloma were focal inflammatory sites, solely observed within the vascular wall, di stributed along the course of the affected vessel. These findings raise the question as to whether pulmonary granulomatous lesions of other origins ar e also localized within the vascular wall. (C) 2000 Academie des sciences/E ditions scientifiques et medicales Elsevier SAS.