Immunohistochemical evaluation of a sarcomatoid hepatocellular carcinoma with osteoclastlike giant cells

BACKGROUND: Malignant liver tumors with osteoclast-like giant cells are rare. A literature search showed 17 previously reported cases that included the following: (1) 8 undifferentiated hepatocellular carcinomas, (2) 5 sarcomatous tumors with osteoclast-like giant cells associated with intrahepatic cholangiocarcinoma or liver cystadenocarcinoma, and (3) 4 sarcomatoid tumors with osteoclast-like giant cells associated with areas of a conventional hepatocellular carcinoma. CASE PRESENTATION: A 68-year-old man presented with a tumor of the right lobe of the liver on ultrasonography and computed tomography. Laparoscopy showed a tumor (diameter, 4 cm) in segments 7 and 8 of the right liver lobe that adhered to the retroperitoneum. The tumor recurred 3 months after liver segmentectomy. Repeat laparoscopy showed diffuse and nodular metastases to the omentum and peritoneum. RESULT: Light microscopy showed that part of the tumor had features of classic hepatocellular carcinoma. Another part of the tumor had a solid sarcomatous pattern with osteoclast-like giant cells that were irregularly distributed between the smaller undifferentiated tumor cells; cells of this part of the tumor were positive for heppar-1. CONCLUSION: Light microscopic findings including osteoclast-like giant cells, and the strong reaction of heppar-1 antibody with cells of the sarcomatous part of the tumor, confirmed that this sarcomatous element was a metaplastic or transformed portion of hepatocellular carcinoma. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6000512901462616 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13000-015-0274-4) contains supplementary material, which is available to authorized users.