Imaging manifestations of hepatic epithelioid hemangioendothelioma

Objective To explore imaging manifestations of hepatic epithelioid hemangioendothelioma (HEH). Methods CT and MR images in 14 patients with HEH proven by histopathology were retrospectively analyzed. Plain and two-phase contrast-enhanced CT scan were performed in 5 cases, non-contrast and multiphase contrast-enhanced MR scan were performed in 7 cases, CT and MRI were both performed in 2 cases. Characteristics of CT and MR T2WI images were classified and analyzed. All lesions were classified into three types: multiple, diffuse and solitary form. Results (1) Multiple form of HEH: 228 lesions were found in 11 patients, including 178 lesions on MRI and 50 lesions on CT. On T2WI, three or two layered-target-signs with hyperintensity core were found in 79.2% (141/178) of the lesions. Three layer-target-sign included hyperintensity core, hypointensity rim and slightly high signal halo from the inside out. Two layer-target-sign included hyperintensity core and slightly high signal halo from the inside out. Characteristics of dynamic contrast-enhanced scan included peripheral two or three layered-rim-like enhancement in 66.3%(118/178) of the lesions; peripheral, gradual rim-like enhancement with enhanced core in 27.0% (48/178) of the lesions; heterogeneously mild enhancement in 2.2% (4/178) of the lesions; centripetal enhancement in 4.5% (8/178) of the lesions. Fifty lesions were found in CT, which showed low density nodules or masses with clear margins. Two-layered-black-target sign were found in 42 lesions in contrast-enhanced images, white-target sign were found in 3 cases, and centripetal enhancement was found in 5 cases. (2) Diffuse form of HEH: in one of the two cases of this type, the lesions could not be separated from normal liver parenchyma, gradual enhancements were found along with the vessels in the center of the lesions. (3) Solitary form of HEH: one case, the lesion showed heterogeneous density in non-contrast CT images and gradual enhancement in contrast-enhanced images. Conclusions We found some imaging characteristics of HEH. Two or three layered-target-sign on T2WI and black-target sign, white-target sign on contrast-enhanced images were unique imaging features of HEH. Key words: Liver neoplasma; Magnetic resonance imaging; Tomography,X-ray computed