Dermatology Questions? Ask an Online Dermatologist.
It sounds that you are really over-reacting with unnecessary worry here!
You don't have any lesion on your skin?
Your twin probably just has a dark colored nevus ( mole) which her doctor biopsied as a precaution ...
She probably does not have a skin cancer and YOU have even less reason to worry ..
I hope that this is helpful for you
Let me know if you have further questions or concerns
I will be happy to get back with you
If my answer has been helpful and to your satisfaction then please remember to leave positive feedback Thank you and Best Regards,
Anthony Bray MD