What is this internal growth that killed my hen? (Graphic photo)

[fishinbim]

I thought my hen was egg bound. She acted like she was egg bound. She passed away last night. My husband did a necropsy on her and we didn't see this coming. All her internals were encompassed by this growth. See picture. What the heck is this? Looks like I had no shot in saving her.

 

[aart]

Tumors.
Had something very similar,
poultry pathologist diagnosed via photos said could be Mareks or Leukosis.
Would need labs done to know for sure.