Was this a tumor or what?

[Anoni Mus]

Yesterday I killed my first chicken because she wasn't laying and was going to eat it, I noticed egg yolks inside but more astonishing I found a huge yellow sac full of veins larger than the average man fist. Was it a tumor?

I discarded the meat just to be safe.

I have another chicken in the same situation, they are likely siblings, could it be genetic? Inbreeding? I bought the eggs and incubated them myself.

 

[SmiYa0126]

Where was it in the first picture?

 

[Anoni Mus]

It was already removed in the first pic, it's just the egg yolks and some organs (and what's that yellow color?)