Suggest Treatment For Tender Bump On Forehead After Injury

my boyfriend recently wrecked while mountain biking and walked away with some deep cuts and scraps on his face and a broken nose, but no internal bleeding or fractures to the skull. Now, 2 weeks later, he began to notice a tender bump forming on his forehead and he was messing with it and pressed on it and heard a "crunching" sound followed by intense pain. what could this be?