Contributed by Jennifer Yoest, MD and Sarangarajan Ranganathan, MD
A 2-year old girl presents with a liver mass. The mass is unifocal and multi-lobulated on imaging and occupies the entire right lobe, displacing the main branches of the portal veins. The serum alpha-fetoprotein is elevated to 680 ng/dL and the only other pertinent finding is an elevated platelet count to 685,000. An open biopsy is performed and representative sections are displayed below:
Hematoxylin and Eosin staining demonstrates small hepatocytes with uniformly round nuclei with no atypia and clear to granular cytoplasm which are arranged in diffuse sheets with a vague canalicular pattern visualized in places. There are scattered vascular structures, but portal tracts are absent. Bile is focally visible. There is little to no mitotic activity within the sampled tumor and extensive counting showed <2 mitoses per 10 high power fields.
Glypican 3 is positive in a fine, granular, pericanalicular pattern.
Beta catenin shows diffusely variably positive cytoplasmic staining and patchy nuclear staining. (Membranous staining is considered normal pattern.)
Glutamine synthetase is positive in a diffuse, cytoplasmic pattern.