Yesterday Two Red/brown Blotches Showed Up On My Husband's Jaw

Yesterday two red/brown blotches showed up on my husband's jaw and eyebrow. For the past few days he has also had unexplained brown spots on hands and arms. He had prostate cancer last year (Stage II), received both chemo and radiation and right now seems to be OK. He is 73 years old, extremely fit, lean and strong. I'm concerned about the spread of cancer, of course.