Tonsillar metastasis from hepatocellular carcinoma: a case report and literature review.

Tonsillar metastasis from hepatocellular carcinoma (HCC) is extremely rare. We report an 84-year-old man with chronic hepatitis B who presented with a right-lobe HCC and portal vein tumor thrombosis. Three months after diagnosis, intrahepatic metastases were treated with transarterial chemoembolization and lenvatinib. Twenty-three months later, he developed blood-tinged sputum; imaging and laryngoscopy revealed a left tonsillar mass with concurrent pulmonary and hepatic progression. Tonsillectomy yielded an undifferentiated carcinoma lesion. Compared with the primary tumor, the tonsillar metastasis lost hepatocyte specific antigen (Hep Par-1) and Arginase-1 expression, showed a markedly elevated Ki-67 index (80%), but retained Glypican-3 and heat shock protein 70 (HSP70). A diagnosis of metastatic HCC was favored based on integration of clinical history, laboratory findings, and pathological immunohistochemistry. In HCC patients, any unusual head and neck lesion warrants suspicion of metastasis; a multi-marker panel is critical for diagnosis, as loss of Arginase-1 does not rule out HCC.