Autopsy evaluation of asbestos exposure: retrospective study of 135 cases with quantitation of ferruginous bodies in digested lung tissue.

In recent years, there has been increased interest in documenting asbestos exposure. The pathologic sine qua non of asbestos exposure has been the presence of "asbestos bodies" in lung parenchyma. In this retrospective study of 135 autopsies done to determine asbestos exposure, ferruginous bodies in digested lung tissue were quantitated by a simplified sodium hypochlorite procedure on fresh or fixed tissue. Of the 131 digested specimens, 26 (20%) showed no ferruginous bodies, 34 (26%) had <5 ferruginous bodies per slide, 7 (5%) had 5 to 10 ferruginous bodies per slide, and 64 (49%) had >10 ferruginous bodies per slide. Ferruginous bodies were identified in hematoxylin-eosin stained sections of lung tissue in only 41 cases (30%). The digestion method described is a simple, reliable, and inexpensive method to assess ferruginous bodies.