My husband of 53 years survived malignant melanoma at the 1973 because of radical surgery, he was only 26 at the time. Now in his mid 70's has had 2 insitu melanomas removed. Although he has regular check ups, at least 3-4 a year for which suspicious growths which are biopsied, and many barnacles are removed or burned, upon a recent checkup he asked for a small but growing growth on his forehead to be biopsied. Like you, his dermatologist said it was nothing and didn't need a biopsy. We have a Cadillac insurance plan so plan so restrictions were not an issue. He insisted based upon his history and yes it was intitu melanoma.
Your photo is helpful because it demonstrates the variety of ways melanoma manifests itself. None of my husband's melanomas looked like your photo. I'll show him you photo as it educates us on the various ways we can spot melanoma.