肝脏上皮样血管内皮细胞瘤的影像学和病理学特征

Hepatic epithelioid hemangioendothelioma： analysis of the correlation of imaging characteristics with histopathological findings

目的分析肝脏上皮样血管内皮细胞瘤（EHE）的影像学和病理学特征，提高对肝脏EHE的认识。方法回顾性分析5例经病理证实的肝脏EHE的CT和磁共振成像（MRI）影像学和病理学特征。结果5例肝脏EHE患者均为多发，共92个病灶。全组病灶均位于肝包膜下2eIn区域内，28个病灶可见包膜凹陷征。3例行MRI检查的36个病灶中，77.8％的病灶T2压脂序列呈晕环征，91．7％的病灶增强扫描序列呈晕环征；91．7％的病灶T2压脂序列可见病灶最外缘环状低信号影，36．1％的病灶肝胆期可见中心或边缘轻度强化。2例行CT检查的56个病灶中，有7个病灶呈典型晕环征。结论肝脏EHE影像学特征以包膜下分布为主，结节可相互融合，可见包膜凹陷征及晕环征；T2压脂序列病灶外缘环状低信号影和肝胆期病灶轻度强化，有助于肝脏EHE的诊断与鉴别诊断。MRI对于病灶内部特征的显示优于CT。

Objective To analyze the imaging characteristics of hepatic epithelioid hemangioendothelioma （EHE） and their correlation with histopathological findings. Methods CT and MRI imaging and histopathological characteristics of five patients with hepatic EHE were retrospectively reviewed and the correlation of their imaging characteristics with pathological findings was analyzed. Results A total of 92 lesions were found in the 5 patients, all presenting with muhiple nodules. All the 92 lesions were located within a 2-cm zone beneath the hepatic capsule, i.e., the shortest distance from the border of lesions to the hepatic capsule, 28 of the 92 lesions showed the ＂capsular retraction＂ sign. 36 lesions were found in three patients receiving MRI. 77.8% of the 36 lesions demonstrated the ＂halo＂ sign on a fat-suppression T2- weighted image, while 91.7% after contrast enhancement. A peripheral dark rim was found in 91.7% of the lesions on a fat-suppression T2-weighted image. In addition, 36.1% of the lesions showed slight internal or edge enhancement at the hepatobiliary phase. In the two patients receiving CT examination, 7 of 56 lesions demonstrated the ＂halo＂ sign. Conclusions Hepatic EHE may manifest as nodular lesions with predilection of peripheral subcapsular growth and nodular confluence, together with ＂ halo＂ sign and ＂ capsular retraction＂. The peripheral dark rim on a fat-suppression T2-weighted image and slight enhancement at the hepatobiliary phase can help to improve the accuracy of diagnosis and differential diagnosis of this hepatic tumor. MRI is superior to CT imaging to depict their intra-lesional characteristics.