Any changes in the color, size, shape, borders, or sensations within a preexisting mole (nevus) is enough of a reason, in my view, for a visit to a Dermatologist (and, in most cases, a biopsy to rule out melanoma).
Sincerely,
Robert A. Wascher, MD, FACS
www.doctorwascher.com
Author, "A Cancer Prevention Guide for the Human Race"