Electron microscopic identity of talc in the liver of a narcotic addict.

In this report we identify the ultrastructural correlate of birefringent crystals that we found in biopsy specimens from an intravenous drug addict and that were presumed to be talc. By electron microscopy the crystals were electron dense and elongated with sharp edges and had an apparent lamination. The crystals were found within portal or granuloma macrophages and were often displaced or associated with section tears and knife marks. Weak electron diffraction patterns were obtained that were consistent with talc.