My Husband Has A Big Lump Protruding Outwards On The

My husband has a big lump protruding outwards on the bottom of his sternum, no doc is of help to give a solution, they seem to ignore it, saying do exercise etc, scans don't show anything, it is painful and he cannot sleep on his side, it seems to 'crush' out more pain that way. He is a heart patient and did not pick his heart condition because this lump pain was disguising it for years. Is there a specialist one can see?