Fibrolamellar Carcinoma With Predominantly Pseudoglandular Architecture: A Potential Diagnostic Pitfall.

Biopsies of liver mass lesions are encountered frequently in general surgical pathology practice. The clinical differential diagnosis is typically hepatocellular carcinoma (HCC) versus metastatic adenocarcinoma. There are a variety of HCC variants that show a range of morphological appearances. The presence of malignant glands in the liver prompts the pathologist to consider adenocarcinoma, either metastatic or primary intrahepatic cholangiocarcinoma. It is important to remember that some variant patterns of HCC can show pseudoglandular growth. In this article, we present a case of fibrolamellar carcinoma that showed predominantly pseudoglandular growth to highlight the importance of a systematic approach and the routine use of a panel of immunohistochemical stains (HepPar1, CK7, and CD68).