These Cells Shouldn't be in a Liver!

What are those eosinophils doing in there?

This was a liver aspirate from a dog with an enlarged liver.  There are tons of intermediate to large sized lymphocytes (not supposed to be in a liver!) which is consistent with lymphoma.

And then peculiarly, there are a good number of eosinophils too. Why are those there?

Well, lymphoma can sometimes cause a paraneoplastic eosinophilic inflammatory response! You probably are most familiar with this type of response with mast cell tumors, but it can also happen in lymphoma cases. So, it all makes sense!