Hemodynamics and progression of a hypervascular focus in a borderline lesion of hepatocellular carcinoma: analysis by angiography-assisted CT and histopathology

Abstract

Purpose: To investigate the hemodynamics and progression of a hypervascular focus (HF) in a borderline lesion by dual-phase CT during hepatic arteriography (CTHA) and reveal the process of the transformation to hypervascular overt hepatocellular carcinoma (HCC).

Materials and methods: This study was performed with the approval of our institutional ethics committee, and informed consent for the retrospective usage of clinical materials was obtained from all the patients. The 121 nodules in 76 consecutive patients with liver cirrhosis and chronic hepatitis showing an HF in a borderline lesion on angiography-assisted CT were analyzed. Hemodynamic changes were observed in 24 patients who underwent repeated angiography-assisted CT. Histopathological analysis was conducted in eight nodules.

Results: HF was classifiable into type A (stain disappeared), B (stain prolonged), C (stain was washed out and corona-like drainage into the outer nodule was seen) and D (stain was washed out and corona-like drainage into the whole outer nodule was seen) on the late phase of CTHA and was seen to progress in this order on follow-up observation. Histopathologically, de-differentiated foci showed significantly higher expression of sinusoidal capillarization and unpaired arteries than background nodules and showed pseudocapsule, compressive and replacing growth at the border of the background nodule.

Conclusion: HF showed multi-step progression and transformation to hypervascular overt HCC.