原发性肝上皮样血管内皮瘤(HEHE)和原发性肝血管肉瘤(PHA)是罕见的间充质肿瘤,具有不同的恶性潜能。而HEHE显示出低至中等的恶性潜能,PHA是一种预后不良的侵袭性恶性肿瘤。了解这些病变的典型影像学特征可能有助于正确诊断;然而,HEHE和PHA的最终诊断是基于组织病理学检查。
有助于诊断HEHE的最典型发现是:存在多个,位于肝脏外围的融合结节(年轻至中年女性),肝包膜的收缩,T2加权图像上明显的高强度,“目标标志”外观,渐进式向心对比度增强,和相对较高的表观扩散系数(ADC)值。在肝胆相(HBP)图像上,超过50%的结节是高信号或等信号。
提示PHA的影像学特征是:转移的发生(肺,脾脏)在诊断时,存在一个大的主导质量和较小的卫星,主要肿块的异质性和出血面积,渐进式对比度增强,与其他恶性肝肿瘤相比,ADC值略有升高。
Primary Hepatic Epithelioid Haemangioendothelioma (HEHE) and Primary Hepatic Angiosarcoma (PHA) are rare mesenchymal tumours with different malignant potential. Whereas HEHE demonstrates low to intermediate malignant potential, PHA is an aggressive malignancy with poor prognosis. The knowledge of typical imaging features of these lesions may facilitate correct diagnosis; however, the ultimate diagnosis of HEHE and PHA is based on histopathologic examination.
The most typical findings helpful in diagnosing HEHE are: Presence of multiple, confluent nodules located at the liver periphery (in young to middle-aged woman), retraction of the liver capsule, marked hyperintensity on T2-weighted images, \"target-sign\" appearance, progressive centripetal contrast enhancement, and relatively high Apparent Diffusion Coefficient (ADC) values. More than ≥50% of nodules are hyper- or isointense on Hepatobiliary Phase (HBP) images.
The imaging features suggestive of PHA are: Occurrence of metastases (lungs, spleen) at the time of diagnosis, presence of a large dominant mass with smaller satellites, heterogeneity and areas of haemorrhage in a dominant mass, progressive contrast enhancement, slightly elevated ADC values as compared to other malignant liver tumours.