It was difficult to find pictures of similar necropsy pictures. Here is one link I found about leukosis:
http://www.thepoultrysite.com/publications/6/diseases-of-poultry/202/lymphoid-leukosis/
Leukosis can cause liver disease. Ascites can be a result of egg yolk peritonitis, liver disease, and...
I am not an expert on necropsies, but in seeing the little bumps everywhere, I would guess that your hen may have had a virus causing cancer, such as lymphoid leukosis or Mareks disease. It would be great if others, such as @casportpony, @rebrascora and others, with more experience chime in...