Osteoclast-like giant cell tumor of the liver.

A 66-year-old male with osteoclast-like giant cell tumor of the liver that arose in the non-cirrhotic liver is presented. The liver tests were almost normal, and plasma levels of alpha-fetoprotein and carcinoembryonic antigen were within normal limits. The findings of liver scan by 99mTc phytate, celiac angiography, and CT scans are described for the first time for this rare neoplasm, showing a large, unresectable liver tumor. Histologically, the tumor mainly consisted of osteoclast-like giant cells and mononuclear cells, which were focally arranged in a vaguely trabecular pattern and sarcomatous pattern. By an electromicroscopic study, however, no definitive evidence was obtained whether it arose from epithelial cells or nonepithelial cells. Various clinicopathological features were described and compared with previously reported cases including two cases arising in the liver.