Under the skin, huge lump of scar tissue on buttocks

I have a fairly large lump of scar tissue under my skin on my left butt cheek. It is very noticeable, even under clothes. I had an extremely bad fall about 4 years ago and that's when it developed. I fell down some stairs on my rear end. Is there anything other than surgery that I can do to reduce the size of the lump? Would cortisone or steroid shots help with such a large lump?