Tummy tuck 7 years ago & scar is thick & feels lumpy on some places, what to do?

There are a number of options here. None of which are always helpful or predictable. And most treatments have risks. To get the most improvement, complete excision and perhaps early radiation treatment may provide excellent results. This is very aggressive, and you may still have regrowth of excessive scar. The resulting scar could potentially be worse. You should consider visiting your plastic surgeon to evaluate the options and especially your expectations of improvement. This would dictate which different methods may be considered.

You may have thick scarring or even a keloid. Go back to your surgeon and see if Kenalog injections might be helpful.