My Three Year Old Son Had A Head Injury About

My three year old son had a head injury about two and a half weeks ago. A heavy door fell on his body and face. He cut his forehead ( between his eyes) and a small cut on his eyelid. He had a swollen bump on his head, bruising and swelling on his face. But know almost all is gone except a small bump in his forehead remains. Any further treatment needed or will the hard bump go away on its own?