Are you sure that's the crop? What does it feel like, hard, soft, like air or fluid? Did this chick start out normally after hatch? Did you hatch it, or was it purchased/shipped?
I think I can see the same spot in your second picture (?), it kind of looks like it's the shoulder where the wing should attach or just above that? I'm wondering if it's a deformity. Was it always this way? In that same picture, second, I think I see the crop on the opposite side in front, and the keel bone also seems to be off center, but it may just be how it's positioned in the picture. Chicks that are malpositioned in the egg can be hatched with deformities from that. I had one a couple of years ago that was malpositioned, had to be assisted to hatch, the keel bone was very abnormal and shaped like a C.