S5882 A Rare Case of Hepatocellular Carcinoma Metastasized to the Mandible

Introduction: Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer-related death. It accounts for 80%-90% of primary liver malignancies and carries a poor prognosis, with a 5-year survival rate of 33% (localized), 11% (regional), and 2% (distant). Extrahepatic metastases most commonly involve the lungs, lymph nodes, and bones, but mandibular involvement is exceedingly rare, occurring in less than 1% of cases. Case Description/Methods: A 65-year-old woman with a history of HCC secondary to hepatitis C and alcohol-related cirrhosis and diabetes mellitus presented with altered mental status and was diagnosed with diabetic ketoacidosis. During hospitalization, she developed an acute, tender preauricular mass with trismus. Examination revealed a 2 cm firm, fluctuant, fixed mass on the ascending mandibular ramus. Computed tomography head showed a lytic lesion in the cortical bone of the mandibular condyle, and maxillofacial imaging confirmed a 2.3 cm by 2.2 cm heterogeneously enhancing mass with bony destruction. A bedside ultrasound confirmed a hypoechoic fluid collection anterior to the ascending ramus. Aspiration yielded 1 mL of blood. Biopsy identified metastatic HCC with tumor cells diffusely positive for glypican-3 and patchily positive for HepPar1, CD10, and AE1/AE3. MRI of the abdomen revealed a 6.0 cm right hepatic lobe mass consistent with HCC, and Alpha-fetoprotein was 1,060 ng/ml. The patient later developed additional scalp nodules concerning for further metastases. Given the disease burden, she was transitioned to comfort care and received 5 sessions of palliative radiation to the right mandible and the right liver mass before hospice discharge. Discussion: HCC is an aggressive malignancy with a high propensity for extrahepatic spread. Metastasis to the oral cavity is rare (1%-4% of cases), often via hematogenous spread, and typically involves the mandible due to its rich vascularization. Clinical presentations are often nonspecific and may mimic odontogenic or soft tissue infections. Radiologically, mandibular metastases appear as destructive, radiolucent lesions with ill-defined borders. Diagnosis requires histopathologic confirmation. Early recognition is critical, as treatment options for advanced HCC are limited to systemic therapy or palliative care. This case highlights the need for a high index of suspicion for metastatic disease in patients with known malignancies and unusual presentations.