I have a dark spot or kind of shade on the left side of my forehead, cause it's not small it almost cover the entire left side if the forehead. And it had been the same way since last year, At that time I've acne marks all over my face. But now most of them have started fading, but this spot haven't showed any change. Recently I've been using cosmetics to improve the complexion which might also have cleared it a bit. But I've read articles over the internet for this symptoms, and now I'm concerned whether it is melanoma. I can provide pictures if it help on figuring out.