What Is The Treatment For Thymoma?

I am a 37 year old, caucasian woman and was just recently diagnosed with Thymoma and need a thymectomy via sternotomy. I was wondering if someone can tell me how long it would normally take before the incisions heals and what are the chances of having a scar after the surgery. I know the answer will be different for each person, but I was just wondering what the average healing time and chances of having a scar are and if there are anything that I can do to improve my chances. Thanks