It looks like a somewhat normal dye density variation that doesn't deserve to be called a defect. Some variation in the rate of dye flow during the coating process, or something like that.
I've seen it before with [I believe, Prodisc manufactured] MCC media. Somewhere in the middle of a 25-pack of 03RG20 [the -R counterpart to MCC 004] I started getting a PIE peak around the 200 MB mark; not as pronounced as in your case, but always present no matter which drive burns the media.
Here are the scans, without the peak [top part of the pack] and with the peak [bottom part of the pack].