Pathological findings in patients with sirolimus toxicity. In case 4, open lung biopsy shows diffuse alveolar hemorrhage represented by collections of hemosiderin laden alveolar macrophages (A, inset) and occasional hemosiderin granules within interstitium, (hematoxylin-eosin, original magnification x100 and x400, respectively). In case 10, open lung biopsy shows pulmonary hemorrhage in association with pulmonary alveolar proteinosis and organizing pneumonia: there are areas with hemosiderin deposition within interstitium (B) and cholesterol granulomas, finely granular proteinaceous material with cholesterol clefting (C) and foci of organizing pneumonia (D) in adjacent alveolar parenchyma, (hematoxylin-eosin, original magnification x100, x200 and × 40, respectively). Computed tomography of the chest at the time of open lung biopsy shows diffuse ground glass and "crazy pavement" opacities (E). Follow up computed tomography in 8 months (F) shows marked decrease in alveolar opacities; both scans are at the level of aortic arch for comparison. In case 16, open lung biopsy shows a combination of diffuse alveolar damage and pulmonary hemorrhage: there are edematous alveolar septae lined by hyaline membranes (G) and hemosiderin-laden macrophages (H) within alveolar spaces (H&E, original magnification x200 and x400, respectively).
Kirby et al. Diagnostic Pathology 2012 7:25 doi:10.1186/1746-1596-7-25