It's hard to clearly make out the defects in the photo.
I've seen 2 issues with the 27" LCD's, most common is contamination due the the ingress of dust. When bad it looks like a cloudy day. The other, not your problem, backlight issues causing the left side of the screen to be darker than the right. Both require LCD replacement to resolve. As already mentioned, the first thing to do is to attach another display to determine if it is an LCD or video problem. If you can't do that, take a screen shot of the effected area, then view it in a good area of the screen. If the problem doesn't show you have an LCD fault.