Yes I had skin cancer several years ago that confused the doctors for months. Initially my dermatologist dismissed it as nothing after looking at it under 100x magnification. The doctor left for vacation and didn't bother to check my results for nearly a month.
Biopsy came back some type of cancer. It was very aggressive and atypical so they had trouble pinning down on the exact type(basal, squamous, etc). I had to have a procedure done to cut it out in two passes. Now I have nearly three inch scar. Part of it was because the surgeon didn't know what the hell she was doing. I'd have needed to go to a plastic surgeon to get it fixed. Fuck it now I look like some villain from a Bond movie.