LIGHT-MICROSCOPY TECHNIQUES FOR THE DEMONSTRATION OF SILICONE GEL

Because of the difficulty in identifying silicone gel in histologic an d cytologic specimens by means of conventional light microscopy, we in vestigated alternative light microscopy techniques, as well as specime n staining and preparation. Specimens from six periprosthetic capsules , one silicone granuloma specimen, and one synovial biopsy specimen ob tained from women with silicone breast implants were cut at 4-, 10-, 2 0-, and 30-mu m sections, stained with a variety of common stains, and correlated with electron probe microanalysis. In addition, a commerci al silicone gel and silicone gel extracted from a previously implanted silicone breast prosthesis were smeared and examined unstained or sta ined with Papanicolaou and Diff Quik. Silicone was noted to be refract ile, nonpolarizable, and nonstainable. Thicker sections prevented sili cone ''dropout'' during processing and increased the contrast between stained tissue and unstained silicone (negative staining). The relativ e ease of silicone identification was greatly increased with non-Koehl er, phase contrast, and darkfield microscopy. Staining the mounting me dia of hematoxylin-eosin-stained sections with a nonparticulate commer cial ink allowed enhanced negative staining detection of silicone gel.