Foreign-body reaction to silastic burr-hole covers with seroma formation: Case report and review of the literature

Because silastic material is one of the most commonly used biomaterials in modern medicine, the biocompatibility of these implants is still a source of long standing controversy. Though several studies have established silastic material as biologically inert, numerous authors have repeatedly described characteristic pathological tissue responses to silicone and its elastomeres. We report a case of foreign-body reaction to silastic burr-hole cover with successive formation of a seroma following resection of an olfactory groove meningioma. Within 30 days postoperatively, the patient developed a marked bulge in the glabbelar region. Histopathological examination revealed a seroma-like lesion obviously caused by a chronic inflammatory allergic reaction to the silastic burr-hole cover. Although the silicone-induced tissue damage clinically shows a wide variability and a conclusive model of pathogenesis is presently not available, the histopathological findings in some patients, in the form of,granulomatous lesions and inflammatory cell response, might partly be due to an immunological reaction. Such a reaction has been previously described both clinically and experimentally, as detected in our patient. In addition, a review of the literature is given.