Abstract
Cholangiolocellular carcinoma (CoCC) is a unique subtype of liver cancer with combined features of hepatocellular and cholangiocarcinoma. A tumor of 33 mm diameter was found in segment 6 of the liver of a woman in her seventies with a history of intravascular large B-cell lymphoma. On her ultrasound (US) images, the tumor was an ill-defined, irregularly shaped hyperechoic nodule. On her contrast-enhanced ultrasound (CEUS) images, the tumor demonstrated heterogenous enhancement on the arterial phase, a wash-out pattern on the portal phase, and a defect pattern on the postvascular phase. The tumor was hypervascular and showed enhancement on computed tomography (CT) during hepatic arteriography (CTHA) and a defect on CT during arterial portography (CTAP). Macroscopy analysis of a resected specimen showed a lobulated whitish firm mass without a capsule. Histopathological analysis revealed that the tumor had irregularly branched, anastomosing glands, with focal dilated glands that were architecturally similar to ductal plate malformation (DPM): irregular distorted glandlike structures with bridge/island formation and cystic dilatation. The tumor showed no mucin production. Immunohistochemistry results were as follows: cytokeratin (CK) 7 (+), CK19 (+), glypocan 3 (focal, +), Hep-par 1 (−), CEA (−), and EMA (+, apical staining pattern). The tumor was diagnosed as CoCC with the DPM pattern. By comparative research analysis between the US imaging and histopathological findings, we estimated that the hyperechoic pattern on B-mode images may be the result of the DPM-like pattern.
