My 5 1/2 year old hen, Ellie, died during the night. She'd been going downhill over the past month and it was expected. She'd always laid humongous, rough and usually thin shelled eggs and after her last molt, did not come back into lay. She had had this small fatty-looking cyst on her bum for a couple of years, same as another hen I have, didn't seem anything too worrisome, even asked a vet about it once. It did not seem to affect either of them. The other hen is fine and laying, a year younger than Ellie was. Over the last month, the cyst grew to a monstrous size, sticking out from her bum, maybe four or five times larger than it began. I thought it was either a fatty deposit, or a mass of ingrown feathers, but didn't want to mess with it in this heat, maybe causing a fly strike on her bum. She passed away last night and when I opened up the cyst, got a surprise and something I'd never seen before; well, one thing I'd seen and one I had not. Here is the cyst as it was a couple of weeks ago-that, plus her watery poop, her being not well, caused her bum to be dirty so we'd have to hose it off periodically: Today, the necropsy photos, so if you are squeamish, DON'T LOOK! I did not cut into her actual abdomen, only the cyst. When I got to the intestines, I quit. They seemed normal. First, the whitish spot was only fatty stuff Then, I cut further, seemed normal muscle and tissue, then suddenly, there was a waterfall of bright yellow gunk, too bright and semi liquidy for just fat, maybe some yolk, too: Then, I found this solid ball with veiny exterior and cut it loose; not unusual, seen it before, filled with either cheesy gunk or fibroid like material or even loose yolk, but not outside the abdomen like this one really was-it was contained inside the cyst formation: Inside the ball, which had a multi layered shell, was what looked like scrambled eggs and pieces of eggshell, not all that astounding from the stuff I've seen, really: The surprise was the next thing I found. I saw a mass and pulled at it. Out came what I thought would be a cheesy mass that I've seen in many, many internal layers over the years, but it wasn't. It was what appeared to be literally cooked white meat chicken, cooked muscle. I've never seen this in any hen I've ever opened up, only the cheesy layered masses of cooked yolk and infection, but this is something you'd see on your dinner plate. WTH? There were three masses of it. After that, the cyst pocket was emptied and I could see only a normal body cavity.