My dad will not go to the doctor at all so I'm trying to get info to determine if I should be concerned or let the matter go. He has a large irregular shaped (like a bag full of marbles) protruding lump approximately 2" in diameter that seems to be getting larger, not smaller. It was fairly slow growing--took months to appear. He says it isn't very painful. There is no skin discoloration of any kind. It is moveable and a combination of hard and soft. It does not appear to yield to pressure. I know that most lumps are not cancerous, but I am concerned about the shape irregularity, the location, the continued growth and that there is no skin discoloration of any kind. Any help?