Treating Dark Skin from Hip and Buttocks Silicone Injections?

Hello .. i am 33 yr old woman who had silcone injected into my hps and buttocks in 1995. i havent experienced any problems . on dizziness. etc. but i have experienced very dark skin in my hip area .. and not my buttocks. thee is no pain atall. only extremely dark area on both sides of my lower part of thighs. it has been dark since 1997. what should i do?