Morphologic characterization of polyvinyl sponge (Ivalon) breast prosthesis

Background. - Although almost all breast implants are made of silicon, some implants, especially the ones used in early augmentation mammoplasty, were made of other materials, one of which is polyvinyl alcohol (commercially known as the Ivalon sponge). The morphology of this type of breast implant and its associated tissue reactions have not been characterized in detail. Materials and Methods. - A pair of polyvinyl breast prostheses implanted 40 years ago in a 66-year-old woman were removed together with their capsules to correct progressive disfiguration. The implants and capsules were radiographed. Sections from these specimens were subjected to routine histologic studies and special stains, including periodic acid-Schiff and Masson's trichrome stains. Results. - The breast implants were composed of crystals with a pathognomonic morphology. By hematoxylin-eosin stain, these crystals were polygonal, colorless, and refractile, but nonbirefringent, and they had a characteristic bubbling internal structure. The crystals displayed a deep-blue color with Masson's trichrome stain and were strongly periodic acid-Schiff-positive, with or without diastase digestion. These crystals appeared isolated or interconnecting and were separated from one another by spaces filled with tissue fluid. The capsules were composed of the same kind of crystals, but they were heavily calcified and associated with dense fibrosis and occasional multinucleated giant cells. Conclusions. - This case serves to emphasize that breast prostheses made of materials other than silicon may be rarely encountered in the surgical pathology laboratory. Although polyvinyl breast implants were abandoned, injection of polyvinyl into various tissues for therapeutic purposes is sometimes indicated. The morphologic features of polyvinyl as detailed in this study should enable prompt and accurate recognition of this material, whether it is in breast implants or other types of tissue.