Thanks for the question, this is pigment left behind in the tissues as bruising and inflammation from the surgery resolves. This is uncommon, but more likely to occur with areas that had much more bruising. Bruising is blood that leached into the surgical area and as the bodies natural mechanisms try to clean up the bruising occasionally the iron pigment (hemosiderin) can stay in the area. Appropriate lasers for brown pigment can help as long as the pigment is close enough to the surface. This can still resolve on its own, but that can take several years not one year. Best wishes going forward
