dark skin patches on feet/ankles?

I have seen 2 doc's with no success. what the hell is this? dark, strange shaped, redish blotches on my feet and growing, a few on my shin and calf areas. I have had them for years, but now they are reproducing and getting bigger. I think it is a form of some skin growth/fungus? the don't hurt or itch, nothing, just look ugly, and it's time to get rid of them. any suggestions at all?