I'm worried my mom has lymphoma, does this sound like it?

My mom woke up monday and had a pain around here collar bone area, closer to the back. and later discovered the whole area is swollen. It came up over night, she can't feel any individuall lumps, it's just the general area is swollen. she did not have the swellin sunday. it hurts when she moves her arm or when its touched, the swelling isn't hard. just very painfull. she is 40 and has no other symptoms of lymphoma. she has no family history of cancer. do you think it could be lymphoma? she has only had it 2.5 days. it is only me who is worried, my dad isn;t nor my mom.