Background: Cutaneous metastases from hepatic neoplasms are rare. Histologic features of hepatocellular carcinoma (HCC) are often poorly differentiated, hindering accurate diagnosis on routine examination by hematoxylin-eosin stain. Antihuman hepatocyte antibody is highly sensitive for HCC but can be strongly expressed in other adenocarcinomas. Albumin in situ hybridization (ISH) is highly specific and sensitive for HCC; in combination with antihuman hepatocyte antibody, it has a diagnostic sensitivity approaching 100%. To our knowledge, the combination of antihuman hepatocyte antibody and albumin ISH has not previously been examined in the context of cutaneous HCC.
Methods: We present histologic findings and results of ancillary studies for three patients with metastatic HCC. These patients had a poorly differentiated cytokeratin-positive cutaneous neoplasm. All three cases were evaluated with antihuman hepatocyte antibody and albumin ISH.
Results: Neoplastic cells were strongly positive for antihuman hepatocyte antibody, and ISH detected albumin messenger RNA in nearly 100% of the neoplastic cells in all three cases.
Conclusions: The combination of antihuman hepatocyte antibody and albumin ISH is highly sensitive and specific for HCC metastatic to skin and is useful in the differential diagnosis of a poorly differentiated cytokeratin-positive neoplasm.