Lymphoepithelioma-like hepatocellular carcinoma

Area of Science:

• Hepatology
• Oncology
• Pathology

Background:

• Lymphoepithelioma-like carcinoma (LELC) of the liver is exceptionally rare, with only nine prior cases reported.
• Previous LELC liver cases were predominantly cholangiocarcinomas and often EBV-positive.
• The etiology and specific subtypes of LELC in the liver remain incompletely understood.

Observation:

• A 56-year-old male with chronic hepatitis C virus (HCV) infection and cirrhosis presented with a liver tumor.
• Surgical resection revealed a 3-cm tumor predominantly composed of undifferentiated carcinoma with significant lymphocytic infiltration, characteristic of LELC.
• Immunohistochemical analysis showed focal positivity for HePar 1, CK19, and CK7, and diffuse positivity for AE1/AE3 in tumor cells.

Findings:

• This case represents the first documented instance of hepatocellular carcinoma (HCC) exhibiting a lymphoepithelioma-like carcinoma (LELC) component.
• Epstein-Barr virus (EBV) in situ hybridization (EBER) was negative in the LELC component.
• The tumor cells demonstrated a mixed immunophenotype, with some hepatocellular and some biliary markers present.

Implications:

• The findings suggest that EBV-negative LELC of the liver may arise through a distinct carcinogenic pathway, potentially linked to chronic viral hepatitis and cirrhosis.
• This case expands the known spectrum of liver malignancies and highlights the importance of comprehensive immunohistochemical evaluation for accurate diagnosis.
• Further research is warranted to elucidate the specific mechanisms driving EBV-negative LELC and to differentiate its pathogenesis from EBV-associated LELC.