A Rare Presentation of Mandibular Bone Metastasis from Primarily Diagnosed Hepatocellular Carcinoma: A Case Report

Hepatocellular carcinoma (HCC), the sixth most frequently diagnosed malignancy, typically metastasizes to the lungs (55%), abdominal lymph nodes (41%), long bones (28%), and brain. Metastasis to the oral cavity, particularly the mandible, is an exceptionally rare phenomenon occurring in <1% of cases. In this case, the patient was presented as metastatic jaw malignancy without preceding any clinical symptoms or diagnosis of the primary intrahepatic tumor. Because these metastatic neoplasms lack pathognomonic clinical or radiological distinctions, they are frequently misdiagnosed as benign dental or maxillofacial conditions, such as periodontal disease or post-extraction complications. Accurate diagnosis is confirmed through histopathological studies identifying clusters of hepatocytes with sinusoid-like blood vessels, alongside immunohistochemistry demonstrating positive staining for human hepatocyte paraffin (Hepar 1) antibody. This report details the clinical course and complex palliative management of a patient whose occult Hepatitis C virus (HCV)-driven HCC first manifested as an aggressive mandibular mass.

A 62-year-old female presented with progressive right-sided mandibular swelling following a routine tooth extraction. A deep tissue jaw biopsy and immunohistochemical profiling confirmed metastatic HCC, Grade 2 (positive for Hepar-1 and Glypican 3). Staging investigations revealed a primary multi-lobar intrahepatic tumor, advanced liver cirrhosis, and portal hypertension secondary to a chronic, previously undiagnosed HCV infection linked to a 1987 blood transfusion. The patient received systemic Lenvatinib and palliative hypofractionated radiotherapy (3600 cGy in 12 fractions) to the mandible. Over 9 months, the disease rapidly progressed, culminating in an emergency admission with a bleeding, exophytic fungating mandibular mass, multi-lobar hepatic progression, left portal vein tumor thrombosis, and a new L3 spinal metastasis.

This case highlights the diagnostic challenge of extrahepatic HCC masquerading as dental pathology and emphasizes the critical role of multidisciplinary palliative care in managing complex end-stage oncological complications.