25/m flared up mole 4 inches below left nipple. went to 2 drs, both said no. ribs around the mole feel bruised. how do i make sure its not cancerous?

Biopsy: The only thing to definitely tell you whether this is cancerous or not is by having a biopsy. An experienced dermatologist can help you recognize the need to have biopsy done or just a follow up. Go to see a dermatologist and discuss further with the doctor.

Biopsy: The best way to be certain it is not cancer would be to get a biopsy sent to pathology. Usually this type of biopsy is done by a dermatologist or surgeon.