Filler substances, some of which are birefringent, used by IV drug users provoke lung lesions as shown in the previous slide. This photo shows foreign substance, possibly talc, as it appears with polarized
light. Pulmonary hypertension results when many small pulmonary arteries become occluded.
A foreign substance is engulfed in a giant cell in this section from the lung of an intravenous drug user. These lesions are usually in juxtaposition with small arteries or arterioles.
From the slide collection of the late Dr. Charles Kuhn