My Son Has Just Started Lifting Weights And Last Night

My son has just started lifting weights and last night truly appearing out if no where felt a lump in the left side of his neck. I have lipomas in my neck and one we have been watching in my breast. my family has them. I am a medic and just checked him out. It Feels like a lipoma. It's movable
And not attached to where the lymph nodes are. He's seeing a dr in the morning. I am freaked out because of everything I am reading online!
Thanks,
Anita