Evaluation of hepatocellular carcinoma spread via the portal system by 3-dimensional mapping

Background/Purpose: The pattern of tumor cell spread via the portal system has not been fully clarified in patients with hepatocellular carcinoma (HCC). This study aimed to evaluate the intrahepatic distribution of cancer cells derived from the main tumor by assessing histological portal invasion and/or intrahepatic metastasis (vp/im). Methods: In 14 patients who underwent anatomical resection of primary solitary HCC <= 50 mm in diameter, vp/im were examined pathologically, and the sites of the lesions were reproduced on preoperative 3D-CT images. The number of vp/im and the distance of each lesion from the tumor margin were also determined. Results: The tumor diameter was <30 mm in seven patients (smaller HCCs) and 30-50 mm in seven patients (larger HCCs). 3D mapping revealed that almost all vp/im were localized to the peritumoral area within one cm of the tumor margin in smaller HCCs, whereas vp/im seemed to spread extensively to the feeding 3rd level portal branches in larger HCCs. The number of vp/im was greater in patients with larger HCCs than in those with smaller HCCs. Conclusions: 3D mapping suggested tumor cells of HCC spread via the portal vein extensively in several cases.