Published online Jun 21, 2015. doi: 10.3748/wjg.v21.i23.7335
Peer-review started: November 15, 2014
First decision: January 22, 2015
Revised: February 10, 2015
Accepted: April 3, 2015
Article in press: April 3, 2015
Published online: June 21, 2015
Processing time: 220 Days and 6.2 Hours
Primary liver carcinosarcoma is rare. Here we report an unusual case of liver carcinosarcoma containing combined hepatocellular cholangiocarcinoma. A mass in the right liver lobe of a 45-year-old man was accidentally discovered by ultrasonic inspection and computed tomography (CT) scan. Surgical resection was performed following a diagnosis of primary liver cancer. Micropathologically, both carcinomatous and sarcomatous elements were present, and diagnosis of liver carcinosarcoma was confirmed. The carcinomatous element consisted of hepatocellular carcinoma and foci of cholangiocellular carcinoma. The sarcomatous element was composed of spindle cells and bizarre cells, as well as foci of osteosarcoma and chondrosarcoma. Hepatocellular carcinoma cells diffusely expressed both hepatocyte specific markers cytokeratin (CK) 8/18 and cholangiocyte specific markers CK19, and sarcoma cells were positive for vimentin. Interestingly, both carcinomatous and sarcomatous cells expressed epithelial membrane antigen. CD117-positive ductular reactions and small undifferentiated cells were observed. A liver progenitor cell origin of the liver carcinosarcoma was proposed.
Core tip: Primary mixed-type hepatocellular-cholangiocellular sarcoma is extremely rare. The histogenetic origin of this tumor is controversial. We report a case with special characteristics and propose a new hypothesis combining stem cell theory and “conversion” theory, which may be more appropriately applied to this case.