Most of us are not good at reading chicken xrays. The crop is near the marking, but probably below it. The esophagus is the dark linedown the left side of the Xray while the trachea is under the neck cartilage. The circle looks to be over the esophagus. There could be a mass there, but there are also air sacs in the region, and those can have pockets of infection. We just are not vets here for the most part. The ones on BYC that do look in are more the dog and cat variety, and may not know chicken xrays that well. Sorry I can’t be of more help. I know it is frustrating.