Primary mixed germ cell tumor of the liver with sarcomatous components

Figure 1 Histological features of mixed GCT of the liver with sarcomatous components. A: Papillary structures resemble yolk sac tumor with Schiller-Duval bodies; B: Rhabdomyoblastic cells in primitive mesenchymal cell components; C: Intestinal-type epithelium embedded in neuroblastoma tissue; D: Acinar structures resembling pancreatic acinar tissue; E: Keratinizing epithelium embedded in primitive mesenchymal tissue; F: Neuroblastoma tissue with rosettes formation [Hematoxylin and eosin (HE) stain; A, × 200; B-F, × 400].

Figure 2 Immunohistochemical features of mixed GCT of the liver with sarcomatous components. A: Strong staining for AFP in the yolk sac tumor component; B: Strong staining for AFP in acinar structures resembling pancreatic acinar tissue; C: Strong staining for α-chymotrypsin in acinar structures resembling pancreatic acinar tissue; D: CD56 positivity in primitive mesenchymal cells; E: Strong staining for desmin in rhabdomyoblastic cells in primitive mesenchymal cell components; F: Strong staining for synaptophysin in neuroblastoma tissue (EnVision Plus stain; A-F, × 400).

Figure 3 Tumor cells possess isochromosome 12p and 12p overrepresentation, which are characteristic of tumors of germ cell origin. FISH showing cells with 2-7 (green) 12p signals and 1-4 (orange) 12 centromere signals in yolk sac tumor (A), and rhabdomyoblastic cells (B). (green = 12p probe; orange = 12 centromere probe; magnification × 1000).