BACKGROUND: Poorly differentiated hepatocellular carcinoma (HCC) has a malignant potential such as frequent microvascular invasion even if the tumor is smaller than 3 cm in diameter. The aim of this study was to clarify the preoperative predictors of poorly differentiated HCC for safe local ablation therapy. METHODS: Sixty-six patients underwent a hepatic resection for solitary small-sized HCC (<or=3 cm) were included in this study. According to the postoperative histological examination, the patients were divided into a "poorly differentiated group" (n = 17) and a "well/moderately differentiated group" (n = 49). This study investigated the clinicopathological factors and imaging findings, and elucidated the predictive factors of the poorly differentiated type. RESULTS: In a univariate analysis, serum hepatitis B surface antigen positive, hepatitis C virus antibody negative, alpha-fetoprotein level, des-gamma-carboxy prothrombin level, and a high contrast-to-noise ratio (CNR) in T2-weighted MR imaging were significantly associated with the poorly differentiate type. In a multivariate analysis, a high CNR in T2-weighted MR imaging was the only independent predictor of the poorly differentiated type. In the postoperative pathological findings, portal vein invasion and intrahepatic metastasis were significantly frequent in the poorly differentiated group. CONCLUSIONS: The CNR in T2-weighted MR imaging is a useful tool to predict poorly differentiated HCC preoperatively.
BACKGROUND: Poorly differentiated hepatocellular carcinoma (HCC) has a malignant potential such as frequent microvascular invasion even if the tumor is smaller than 3 cm in diameter. The aim of this study was to clarify the preoperative predictors of poorly differentiated HCC for safe local ablation therapy. METHODS: Sixty-six patients underwent a hepatic resection for solitary small-sized HCC (<or=3 cm) were included in this study. According to the postoperative histological examination, the patients were divided into a "poorly differentiated group" (n = 17) and a "well/moderately differentiated group" (n = 49). This study investigated the clinicopathological factors and imaging findings, and elucidated the predictive factors of the poorly differentiated type. RESULTS: In a univariate analysis, serum hepatitis B surface antigen positive, hepatitis C virus antibody negative, alpha-fetoprotein level, des-gamma-carboxy prothrombin level, and a high contrast-to-noise ratio (CNR) in T2-weighted MR imaging were significantly associated with the poorly differentiate type. In a multivariate analysis, a high CNR in T2-weighted MR imaging was the only independent predictor of the poorly differentiated type. In the postoperative pathological findings, portal vein invasion and intrahepatic metastasis were significantly frequent in the poorly differentiated group. CONCLUSIONS: The CNR in T2-weighted MR imaging is a useful tool to predict poorly differentiated HCC preoperatively.