Light microscopy techniques for the demonstration of silicone gel

Because of the difficulty in identifying silicone gel in histologic and cytologic specimens by means of conventional light microscopy, we investigated alternative light microscopy techniques, as well as specimen staining and preparation. Specimens from six periprosthetic capsules, one silicone granuloma specimen, and one synovial biopsy specimen obtained from women with silicone breast implants were cut at 4-, 10-, 20-, and 30-microns sections, stained with a variety of common stains, and correlated with electron probe microanalysis. In addition, a commercial silicone gel and silicone gel extracted from a previously implanted silicone breast prosthesis were smeared and examined unstained or stained with Papanicolaou and Diff Quik. Silicone was noted to be refractile, nonpolarizable, and nonstainable. Thicker sections prevented silicone "dropout" during processing and increased the contrast between stained tissue and unstained silicone (negative staining). The relative ease of silicone identification was greatly increased with non-Koehler, phase contrast, and darkfield microscopy. Staining the mounting media of hematoxylin-eosin-stained sections with a nonparticulate commercial ink allowed enhanced negative staining detection of silicone gel.