Hepatocellular carcinoma with characteristic mucin production: a case report

Abstract

We present a unique case of hepatocellular carcinoma with mucin-producing gland formation. A 53-year-old man with hepatitis B infection presented with weight loss for the past month. Computed tomography demonstrated a 10 × 9.8 cm mass in the right hepatic lobe accompanied by cirrhotic changes in the hepatic parenchyma. Right hepatectomy was performed, and the tumor cut surface showed a poorly-circumscribed, white to pink tumor with numerous nodules and extensive necrosis. Microscopically, the tumor was composed of thick trabeculae and large, irregularly-shaped islands, both of which were filled with pleomorphic eosinophilic hepatoid cells or gland-forming columnar cells with mucin production. Those cells were immunoreactive for cytokeratin 19 in both the trabeculae and the glands. In some tumor cells, limited immunoreactivity for cytokeratin 7, epithelial membrane antigen and carcinoembryonic antigen was noted. The cells forming thick trabeculae were focally positive for hepatocyte paraffin 1 and alpha-fetoprotein. We suggest that this tumor shows bidirectional differentiation into hepatocytes and cholangiocytes, supporting the concepts that human hepatocarcinogenesis can be based on transformation of progenitor cells which can imply divergent differentiation.

Variants of Hepatocellular Carcinoma

“…The resection specimen described by Lee et al (2009) displayed a poorly circumscribed, firm, white to pink nodular tumor. Histopathology revealed HCC with solid and trabecular components and extensive geographical necrosis.…”

“…Much less common are primary liver carcinomas with a dual phenotype, i.e., having a cell lineage expressing both hepatocyte and cholangiocyte features in the same cells, and not representing primary liver of intermediate phenotype. Such a situation, termed hepatocellular carcinoma (HCC) with mucin production has been first described in 2009, based on a 53-year-old Korean man with liver cirrhosis showing on CT a 10 Â 9.8 cm heterogeneously enhancing mass in the right liver lobe (Lee et al 2009). Based on the distinct histopathology of this tumor (see below), the authors classified the lesion as liver tumor of dual differentiation, different from combined HCC/CC.…”