I do not have PCOS or diabetes, but I did have the dark skin there ("Another": on the inner thigh up by your um, crevice, I guess I can say safely?
). And good news for all (esp. me), it went away!!
I know that that was a big concern for me when I was heavier. I hated it and until you mentioned it, utahgirl, I hadn't even though about it for ages. Out of sight, out of mind and gone forever.