Note from ADMINS: Our deep condolences on your loss. Lucky Rescue is right Lincoln was very lucky to have you.
Since our vet did answer this question, perhaps it will help others.
Answer from Dr. Van Lienden:
A biopsy will be required; some tumors/masses exfoliate easily when an ultrasound guided needle aspirate is done, and the diagnosis is readily obtained.
Other times, these needle biopsies do not collect anything diagnostic, especially if the tumor/masses do not exfoliate cells easily. You are likely dealing with lymphoma, and this could account for the inappetence (rather than hepatic lipidosis, as was likely the "fatty liver" you were referring to). However this just an over-the-fence diagnosis, these could also be multiple abscess secondary to various bacterial/parasitic/fungal agents, as well as other causes for these x-ray silhouettes/"masses".
For the sake of discussion, if there is significant tumor dispersal, then chemotherapy will be the likely treatment of choice--as opposed to hospice.
But you need an accurate diagnosis, therefore the biopsy sample collected will be key to the solution.
Dr. Van Lienden
Dr. Raymond Van Lienden DVM
The Animal Clinic of Clifton
12702 Chapel Road, Clifton
Virginia, U.S.A. 20124