A 12 year old male castrated Norfolk Terrier presented to the Cornell University Hospital for Animals' Community Practice Service for a geriatric wellness exam and routine blood screening. Prior to this appointment, the patient had no significant medical history and had been doing well at home. The physical exam was insignificant aside from mild periodontal disease. Routine CBC and Chem panel were performed, which revealed significantly increased liver enzyme activity, hypoalbuminemia, hyperglobulinemia, and a left shift. Further workup with the Cornell University Internal Medicine Service was recommended. Upon presentation to the Internal Medicine Service, cranial organomegaly and a tense abdomen were palpated during physical exam. A repeat CBC and liver panel revealed a moderate thrombocytopenia, hyperproteinemia, hypoalbuminemia, and significantly elevated liver enzymes. A coagulation panel showed prolongation of aPTT, as well as increases in fibrinogen and D-dimer. Urinalysis was unremarkable aside from some mild proteinuria. Abdominal ultrasound revealed a large, heterogenous, cavitated mass originating from the left side of the liver. A fine needle aspirate was performed, the results of which were equivocal as to the type of tumor present (hepatocellular carcinoma vs. histiocytic sarcoma). Surgery was recommended to remove the mass and submit it for histopathology in order to obtain a definitive diagnosis. Further staging with 3 view thoracic radiographs did not show evidence of pulmonary metastasis. A quadrate liver lobectomy was performed. The entire quadrate lobe and a biopsy from the left lateral liver lobe were submitted for histopathologic analysis. The results of this analysis revealed that the definitive diagnosis was hepatocellular carcinoma. The patient recovered uneventfully from surgery and had normal liver enzyme values as of his last recheck appointment. This presentation reviews normal liver anatomy and discusses the classification schemes, clinical signs, diagnosis, treatment, and prognosis of hepatocellular carcinoma. The pathologic analyses associated with this case are also described. One of the themes of this presentation will be how multiple services within the Cornell University Hospital for Animals (CPS, Internal Medicine, Imaging, Soft Tissue Surgery, Clinical Pathology, Anatomic Pathology) worked together to achieve a desirable outcome for this patient.