Actually, I was going to suggest you do a portupgrade to ghostscript and force it to rebuild dependencies, but I suppose you've already deinstalled ghostcript, so I don't think that will work.
At this point, I think I would recommend deleting all of your installed packages and start installing ports from scratch. You could keep manually reinstalling dependencies until it works, but who knows how deep this problem goes. It could very well be quicker just to start over. Sorry, it's not the preferred answer, but I don't have the expertise to pinpoint exactly where the problem is.