Malignant Blue Nevus vs Malignant Melanoma

    77-year-old male, with history of  who presented for changing lesions on left forehead and right temple. These areas have been enlarging and thickening over the last few years.  Review of his history showed that he had first lesion on the vertex scalp excised 15 years ago, this recurred locally that and was thought to be melanoma.  Over multiple years he has had worsening of blue pigmentation on his forehead and temples, but no distant lesions or systemic symptoms have developed.