Overgrowth of fat autotransplanted for correction of localized steroid-induced atrophy.

A case is presented in which regional subcutaneous atrophy in the lateral thigh after steroid injection was treated with autologous fat grafting. More than 1 year after treatment, an increase in the volume of the transplanted site necessitated a secondary procedure to debulk the area. We believe that this is a case in which the transplanted adipocytes (or preadipocytes) survived and subsequently (for an unclear reason) increased significantly in volume. This case report supports the cell survival theory of fat autotransplantation. Animal studies using radioisotope-labeled lipocytes might provide further understanding of the mechanisms of fat graft "survival."