There is
absolutely no shame in a son crying in front of their mother in instances such as this. Do not feel like you will make things worse by it. She needs your support just as much as you need hers. The hardest thing to do is stay positive. Keep your spirits up and things will hopefully come out alright. It is one thing when someone has it and doesn't know. Look at it this way, now they Know what it is, they can start to treat it. Hopefully they can stop it from spreading, or go in and surgically remove it.
Hoping for the best for you and your family.