Can Melanoma Reoccur, With Black Spots On Toe?

My husband had melanoma on his back 33 years ago----successful surgery. Now anytime he gets some spot I freak out !! He has a tiny black spot on the TOP of his small toe. I looked through a magnifiying glass and it is not on the underside of the toe. It almost looks as if you could scrape it off? Could this be melanoma?