肝细胞腺瘤的影像表现及与病理结果的对照分析

Imaging characteristics of hepatocellular adenoma compared with pathologic findings

目的探讨肝细胞腺瘤的影像特征及其相关病理基础。方法回顾性分析经手术病理证实的12例肝细胞腺瘤患者资料，根据肿瘤的病理特性分为脂肪变性型、炎细胞浸润伴血窦扩张型、异型细胞型和不典型肝细胞腺瘤4类亚型，分析不同病理亚型肝细胞腺瘤的CT及MR表现特征并与病理结果进行对照分析。结果脂肪变性型共4例，其中2例行CT扫描，1例行MR扫描，1例同时行CT加MR扫描。CT平扫1例，表现为低密度；增强扫描3例，动脉期、门静脉期及延迟均为低密度；MR平扫2例，T1WI正相位均为等信号，T1WI反相位均为低信号，T2WI均为中低信号；增强扫描1例，动脉期、门静脉期及延迟期均为低信号。炎细胞浸润伴血窦扩张型共2例，均行MR扫描，1例行CT扫描；CT平扫为低密度且CT三期动态增强均表现为高密度；MR平扫2例，T1WI1例为等信号、1例为低信号，T2WI均为中高信号，MR增强扫描，2例三期动态增强呈不均匀渐进性持续强化，均为高信号。异型细胞型共3例，CT平扫2例，1例为均匀低密度、1例为均匀等密度；CT增强扫描3例，动脉期均为高密度，门静脉期强化程度减低（2例为高密度、1例为等密度），延迟期密度进一步减低（2例呈略高密度、1例呈略低密度）；1例同时行CT及MR扫描，MR平扫T1WI为等信号，T2WI为中高信号。不典型肝细胞腺瘤共3例，1例同时行CT和MR扫描，2例仅行MR扫描。1例CT平扫为均匀低密度，增强扫描动脉期为高密度，门静脉期为等密度，延迟期为略高密度；3例MR平扫，T1WI为2例为等信号，1例为中高信号（1／3例）；T2WI为中高、中低、等信号各1例；增强扫描2例，动脉期均为高信号，门静脉期呈中低、中高信号各1例，延迟期呈等信号和中低信号各1例。结论肝细胞腺瘤的影像特征与其病理组织特征密切相关。

Objective To retrospectively compare CT and MR features of hepatocellular adenoma with pathologic findings. Methods Twelve patients with histopathologically proved hepatoeellular adenoma were classified on the basis of pathologic and genotype phenotype findings into four groups： steatotic type, cytological abnormality type, telangiectatic adenoma with inflammatory infiltrates type and atypical adenoma type. The CT and MR features of each type were reviewed retrospectively compared with the pathological results. Results In this retrospective study, 12 patients were examined with CT （8 patients） and MR （8 patients）. Among 12 patients, 4 patients showed a steatotic type. One patient showed hypo-density on the non-enhanced CT and 3 patients demonstrated hypo-density on all phases of the post-contrast scans. Two lesions showed iso-intense signal on the in-phase T1WI with signal dropout on the out-of-phase T1WI, and hypo-intense signal on the T2WI with fat suppression sequences. One lesion demonstrated moderate hypo- intense signal on all phases of the post-contrast MRI scans. Two patients with the telangiectatic adenoma inflammatory infiltrates type were found. One patient showed hypo-density on the non-enhanced CT scans and hyper-density on all phases of the post-contrast CT scans. One patient demonstrated iso-intense signal and the other hypo-intense signal on the T1WI, and both displayed moderate hyper-intense signal on the T2WI with fat suppression sequences and hyper-intense signal with gradual enhancement on all phases of post-contrast MR scans. There were 3 patients with a cytological abnormality type. One patient appeared hypo- density and 1 patient showed uniform iso-density on non-enhanced CT scans. All patients who had undergone contrast-enhanced CT scans were found to have hyper-density on the hepatic arterial-dominant phase and became slightly lower on the portal venous phase. On the delay phase the density reduced further. One mass showed iso-intense signal on the T1 WI and hyper-intense signal on the T2WI with fat suppression sequences. There were 3 patients with an atypical adenoma type. One patient appeared uniform hypo-density on the non- enhanced CT and hyper-density on the hepatic arterial-dominant phase and became iso-dense on the portal venous phase. On the delay phase, it was slightly hyper-dense. Two out of the three lesions showed iso- intense and one hypo-intense signal on the in-phase T1 WI, and hypo-intense, hyper-intense, and iso-intense signal on the T2WI with fat suppression sequences, respectively. Two patients examined on all phases of post-contrast MRI scans. The result was similar to the CT findings. Conclusion The imaging features of hepatocellular adenoma are closely associated with pathological characteristics.