SYNOVIAL METAPLASIA OF A PERIPROSTHETIC BREAST CAPSULE

A 48-year-old woman presented for reconstruction mammoplasty 5 years a fter undergoing a mastectomy for breast carcinoma. She underwent tissu e expansion, with subsequent placement of a permanent silicone implant , removal of the permanent implant because of asymmetry, and further t issue expansion for another attempt at permanent silicone implant plac ement. The periprosthetic breast capsule surrounding the initial perma nent implant consisted of a lining intima, subintima, and fibrous caps ule consistent with synovium on light microscopy, immunohistochemical studies, transmission electron microscopy, and scanning electron micro scopy. Silicone was localized intracellularly within the lining cells and extracellularly within the fibrous capsule by electron probe micro analysis. We believe that this case represents synovial metaplasia of a periplosthetic breast capsule that was most likely induced by repeat ed manipulation and silicon exposure from silicone gel leakage and the prosthetic Silastic shell.