Recently had a mole on the back of my neck removed.after 2 weeks it has grown back black as well as with a red ring around it. could this be dangerous?

Need more info: All depends on how the mole was removed and was it sent for microscopic examination? Did the doctor do a punch biopsy or cut it out with a scalpel and then suture it closed? The red ring could be indication of beginning infection. Please get back to the doctor who took the mole off and ask him/her the answers to the questions I just posed.