Bone fragment emboli in the lungs of patients undergoing bone marrow transplantation

In a study of biopsy and autopsy specimens from the lungs of patients undergoing bone marrow transplantation, we noted the presence of hematoxyphilic material within pulmonary vessels. This material, which consisted of calcium, was observed in arteries, arterioles, and capillaries. There were 12 specimens (two from open lung biopsies and 10 from autopsies) and all showed these emboli of calcified fragments. These bony spicules are derived from bone fragments in the grafted marrow and not from degenerative changes in the fatty marrow. The emboli are not associated with any significant pathologic change.