Adult with Painful Lesion That Enlarges and Darkens

An 80-year-old man reports waking up with a localized area of erythema on his forehead. He says that he did not worry about it until the lesion slowly became white and then started turning blue over a few hours. He says that the lesion is painful and is getting larger and darker. He reports no headaches, muscle pain, abdominal pain, sweating, or tremors. View the image taken (Figure 1) and consider what your diagnosis would be.