Chick has swollen neck on one side

[wefroggy]

One of my 3 week old Blk Cochins has a swollen neck that extends to from the front left to the back left. She looks like a hunchback. It feelsvery warm but not hot and soft. We recently moved all the chicks into their new area in the chicken house. Before that she was fine. she is eating, drinking and active and all the other chicks are fine. They have pine shavings for litter which is what I used before I moved them.
I have tried to find info in my chicken books, but don't even know where to begin. Any help would be great.

 

[Ravynia]

I have a Golden Sex-Link with a swelling to the left side of her neck. It's about the size of a ping pong ball and it's very hard and warm.

She's had it for a while now. In fact, I didn't notice it in the store where I got her... but a couple hours after I got her home I noticed it at that time it was about the same size as the tip of my thumb.

I thought maybe it was a full crop, but it's too high in the neck and it's gotten bigger...

 

[wefroggy]

Update, I went out to take another look after reading about crops, that's not it. It feels like it is full of air and it moves around if I touch it. Like there is an air bubble below her skin.