Thank you all so much for the prayers and thoughts. They worked! Jack is fine! We got an early time slot! He was SO BRAVE!
The lump is a BENIGN "lymphatic abnormality" which means his lymph vessel/vessels are swollen up. This is a thing that happens, in the sense that the surgeon who specializes in the lymphatic system was all, "Oh, yeah, one of these." But it's a weird one of those because it's not squishy. She thinks that maybe there's a blood clot in there or something. And since it is BENIGN BENIGN BENIGN we can give it a month or so to be resorbed and if it is, we get to do nothing! If it doesn't go away by itself, he'll have to have surgery, but the surgery will be no big deal because it's really close to the surface.
Seriously, guys, he was a super trooper. He got put under at about 12:10, and he didn't start complaining about being hungry till 11:00 or so, and it was only a few complaints at that. He got a little scared when they put the gas mask on him, and *I* got a little teary when we walked away from him lying there, so small on the gurney, surrounded by scary medical equipment and such. But I was otherwise a super trooper also. As was Andrew. And Nora, who spent her longest time ever away from me and apparently didn't give her respective grandparents much trouble at all.
So thank you so much everyone.
I need some wine.