Abstract:Granuloma formation and chronic inflammation are local reactions that are associated with implantation of medical grade silicone. These responses lead to capsular contraction, pain, and cosmetic problems. In addition, there have been a few reports of connective tissue disease in patients with silicone gel‐filled implants. The purpose of this paper is to raise the possibility that local responses to silicone gel‐filled implants are mediated by fat necrosis.Results of histologic findings and patient records in six patients indicate that patients experiencing implant leakage or failure exhibited classic signs of a foreign‐body response, including the presence of giant cells and foamy macrophages. Most of the observed vacuoles were empty and appeared similar to enucleated fat cells, although some contained foreign material. These observations suggest that the physical presence or degradation products of the implants may have elicited fat cell necrosis that contributed to the chronic inflammatory response. In contrast, patients with intact implants showed no signs of a chronic foreign‐body response. None of the patients in this study demonstrated any systemic complications.It is concluded that although there have been numerous reports of empty vacuoles containing silicone that are either derived from the membrane that surrounds the implant or from the gel, there are no reports linking these vacuoles to the vacuoles seen in fat tissue necrosis, even though histologically the two processes are morphologically similar. Therefore, it is important to ask whether some of the adverse reactions observed with silicone gel‐filled implants may be mediated via fat cell