Hi, my son has had this lump on his lower back for some time. It seems to have gotten bigger and I am concerned about it. For the past two weeks he has not wanted to lay on it or sit. In the past he has been uncomfortable off and on but not for as long as he has been this time. When I push on it he doesn't care so it must be the way he moves on it and the pressure. He has severe CP so this makes life very difficult. Any ideas what it could be?