Fibrolamellar Hepatocellular Carcinoma with Cytokeratin 7 Expression: A Case Report

ABSTRACT

Fibrolamellar carcinoma (FLC) is a rare variant of hepatocellular carcinoma (HCC). A 26-year-old female presented a hepatic mass and mild elevation of liver enzymes. Viral markers were negative, and levels of tumor markers were normal. Radiologically, the mass was well demarcated with central dot-like calcification and hypervascularity. Under the diagnosis of hepatocellular carcinoma, right lobectomy was performed. The tumor was grayish yellow with central fibrosis and focal hemorrhage and invaded a septal bile duct. Non-neoplastic liver was unremarkable. Microscopically, the tumor consisted of large polygonal cells in sheets, cords, and pseudoglands that were interwound by dense collagenous stroma. Tumor cells had abundant deeply eosinophilic cytoplasm and large nuclei with prominent nucleoli. Intracellular bile pigments and pale bodies were present. Tumor cells were diffusely immunostained for cytokeratin 7 (CK7), but not for cytokeratin 20 (CK20). Strong expression of CK7 in the present case suggests dual differentiation of FLC.