Sarcomatoid transformation is a rare but
well documented change that may occur in intrahepatic
cholangiocarcinomas.We report a tumor of this type to
illustrate the difficulties in properly diagnosing cholangiocarcinoma
when only the sarcomatous component
is sampled by transcutaneous needle biopsy. The
proper diagnosis of the tumor was suggested by finding
the expression of cytokeratin 7 in the sarcomatous
spindle cells. The surgically resected tumor comprised
a spindle cell sarcomatous and an adenocarcinomatous
component accounting for approximately 30% and
70% of the total tumor mass respectively.