Suggest Treatment For Hard Lump On Side Of Neck

My 15 yr old grandson . developed a hard lump on the side of his neck a few days ago . My daughter took him to Doctor , they are doing labs , and gave him a rocephin shot and a Zpak , 4 pills at one time . He says its not really painful , but he has lost 14 pounds in one month . Awaiting lab results now . My daughter is scared to death that they may be thinking cancer . Can you help ? Other than a decrease in his appetite , he is not having any other symptoms,thank you !