Oral metastatic hepatocellular carcinoma: a changing demographic in Europe and North America. Immunohistochemical advances in the microscopic diagnosis.

The incidence of hepatocellular carcinoma has shown an alarming increase in North America and Europe since 1980, as has the incidence of reported metastases to the oral region. Consequently, it is important that head and neck health care specialists be familiar with recent epidemiological trends and the histologic and recent immunohistochemical advances in the diagnosis of this deadly malignancy. Histologic features are reviewed, and recent advances in the immunohistochemical differential diagnosis are detailed and illustrated in two cases. A panel of immunohistochemical stains is recommended, some or all of which may be useful to differentiate poorly differentiated or pseudoglandular hepatocellular carcinoma from other metastatic adenocarcinomas to the oral and maxillofacial region.