Is a Bleeding Keloid Cancerous?

Keloids can become injured just like normal skin.  Bleeding is not a sign of cancer in a keloid, but non-healing wounds should prompt a visit to your plastic surgeon. 

Your keloid is bleeding due to its size and location. Looking at the picture, there is a low probability that it is cancerous. I would recommend removal followed by compression earrings and possibly local radiation to prevent the keloid from coming back.

I would say it is very unusual for a keloid to bleed. I hope that you will take yourself to a physican promptly who will remove it for you.
Take care of yourself!