Post-transplantation hepatocellular carcinomarecurrence： Patterns and relation between vascularity anddifferentiation degree

Abstract

AIM： To evaluate the relationship between hepatocellularcarcinoma （HCC） vascularity and grade; todescribe patterns and vascular/histopathologicalvariations of post-transplantation recurrence.METHODS： This retrospective study included 165patients （143 men, 22 women; median age 56.8 years,range 28-70.4 years） transplanted for HCC who had afollow-up period longer than 2 mo. Pre-transplantationdynamic computed tomography or magnetic resonanceexaminations were retrospectively reviewed, classifyingHCC imaging enhancement pattern into hypervascularand hypovascular based on presence of wash-in duringarterial phase. All pathologic reports of the explantedlivers were reviewed, collecting data about HCCdifferentiation degree. The association between imagingvascular pattern and pathological grade was estimatedusing the Fisher exact test. All follow-up clinical andimaging data were reviewed for evidence of recurrence.Recurrence rate was calculated and imaging featuresof recurrent tumor were collected, classifying early andlate recurrences based on timing （〈 or ≥ 2 years aftertransplantation） and intrahepatic, extrahepatic and bothintrahepatic and extrahepatic recurrences based on location. All intrahepatic recurrences were classified as hypervascular or hypovascular and the differentiation degree was collected where available. The presence of variations in imaging enhancement pattern and pathological grade between the primary tumor and the intrahepatic recurrence was evaluated and the association between imaging and histopatholgical variations was estimated by using the χ 2 test. RESULTS： Of the 163 patients with imaging evidence of viable tumor, 156 （95.7%） had hypervascular and 7 （4.3%） hypovascular HCC. Among the 125 patients with evidence of viable tumor in the explanted liver, 19 （15.2%） had grade 1, 56 （44.8%） grade 2, 40 （32%） grade 3 and 4 （3.2%） grade 4 HCC, while the differentiation degree was not assessable for 6 patients （4.8%）. A significant association was foun