A 4-year-old Holstein dry cow was evaluated for relatively non-specific clinical signs of inappetance, weight loss, scant manure production, and weakness. Initial exam findings revealed ketosis and a possible abdominal mass. Imaging results showed multiple abnormal abdominal structures, which were considered to be consistent with focal peritonitis. While hospitalized, the cow was medically managed with intravenous fluids, antibiotics, flunixin meglumine, and force-feeding. However despite therapy, her condition declined and she developed signs consistent with a bleeding abomasal ulcer. The owner elected euthanasia and necropsy results revealed multicentric lymphoma. The cow was reportedly bovine leukosis virus (BLV) negative; a finding which was supported with a repeat BLV ELISA (Enzyme-Linked ImmunoSorbent Assay). The signalment, clinical signs and necropsy findings were consistent with enzootic bovine leukosis, however the development of lymphosarcoma was not associated with BLV infection. Thus, a diagnosis of sporadic multicentric lymphosarcoma was considered appropriate.