Do you know what would cause something like this?Let me say I have not done many necropsies or butchering, but that looks like an adenoma, a smooth round growth, that looks similar to to tissue in which you found it. However there look to be spots on it which probably are fibrosis or scar tisue inside the adenoma, which can be common with them. Hopefully others with more experience will chime in, or any vets out there lurking.