Hello My Husband Noticed A Bruse On His Upper Right

Hello my husband noticed a bruse on his upper right arm, kind of longish 2 to 4 inches, it king of traveled down his arm to the elbow then his hand was slightly swollen, It went away and now it has come back. he does not have a lump under his arm, and does not remember injuring it. could it be a torn muscle? Should we be concerned?