A case of a resectable single hepatic epithelioid hemangioendothelioma with characteristic imaging by ADC map

Hepatic epithelioid hemangioendothelioma: Update on diagnosis and therapy

With an estimated incidence of only 1-2 cases in every 1 million people, hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular endothelial cell tumor occurring in the liver and consisting of epithelioid and histiocyte-like vascular endothelial cells in mucus or a fibrotic matrix. HEHE is characterized as a low-to-moderate grade malignant tumor and is classified into three types: solitary, multiple, and diffuse. Both the etiology and characteristic clinical manifestations of HEHE are unclear. However, HEHE has a characteristic appearance on imaging including ultrasound, magnetic resonance imaging, and positron emission tomography/computerized tomography. Still, its diagnosis depends mainly on pathological findings, with immunohistochemical detection of endothelial markers cluster of differentiation 31 (CD31), CD34, CD10, vimentin, and factor VIII antigen as the basis of diagnosis. Hepatectomy and/or liver transplantation are the first choice for treatment, but various chemotherapeutic drugs are reportedly effective, providing a promising treatment option. In this review, we summarize the literature related to the diagnosis and treatment of HEHE, which provides future perspectives for the clinical management of HEHE.

The Feature of Solitary Small Nodular Type of Hepatic Epithelioid Hemangioendothelioma

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare tumor. Preoperative diagnosis of HEHE is difficult because it does not manifest specific symptoms or tumor markers. We report a resected case of small and solitary HEHE. The patient, a 74-year-old man, had undergone surgical resection for left renal cell carcinoma 20 years ago. During follow-up, a tumor approximately 1.3 cm in diameter was detected by computed tomography (CT) at liver segment VIII. It showed isodensity in the arterial phase, low density in the portal venous phase, and homogeneous enhancement in the late phase on CT and magnetic resonance imaging (MRI). We performed hepatic resection of the right hepatic vein drainage area. A pathological diagnosis of HEHE was made. Although small and solitary HEHE is rare, an enhancement pattern in each phase on CT and MRI, using contrast media, can yield clues for the diagnosis of HEHE.

NEDD4 promotes cell growth and migration via PTEN/PI3K/AKT signaling in hepatocellular carcinoma

The novel E3 ubiquitin-protein ligase neural precursor cell-expressed developmentally downregulated protein 4 (NEDD4) has been implicated as a crucial factor promoting the tumorigenesis of several types of cancer. The present study investigated the oncogenic role of NEDD4 in hepatocellular carcinoma (HCC) by targeted small interfering RNA silencing of the tumor suppressor phosphatase and tensin homolog (PTEN). Using normal hepatocyte and HCC cell lines, the influence of NEDD4 depletion on proliferation and migration as well as on the PTEN/phosphatidylinositol-3-kinase/protein kinase B signaling pathway was assessed. Additionally, the expression of NEDD4 was assessed in HCC specimens from 78 patients. The in vitro immunohistochemistry results indicated that NEDD4 protein expression was higher, but PTEN expression was lower, in HCC cells compared with normal hepatocytes. The results from the MTT assay, wound healing experiment and Transwell assays demonstrated that NEDD4 depletion lead to decreased proliferation and migration ability of HCC cells. Results from western blotting and immunofluorescence demonstrated that silencing of NEDD4 disrupted the PTEN/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in HCC cells. A total of 55 (70.5%) of the HCC specimens stained positive for NEDD4 and expression significantly correlated with tumor size (P=0.047), differentiation degree (P=0.032), vascular invasion (P<0.001), and lymph node metastasis (P=0.005). Thus, NEDD4 appears to perform a critical role in promoting the proliferation and metastasis of HCC via activation of the PTEN/PI3K/AKT signaling pathway; as such, NEDD4 may be a promising target for novel treatments of HCC.

Typical CT and MRI signs of hepatic epithelioid hemangioendothelioma

To investigate the typical magnetic resonance imaging (MRI) and computed tomography (CT) features of hepatic epithelioid hemangioendothelioma (HEH), the CT and MRI findings of 14 histopathologically confirmed cases of HEH were retrospectively analyzed. Non-contrast and dynamic contrast-enhanced scans were conducted in all cases. A total of 229 lesions were detected in the 14 cases. All cases were classified as one of three types: (i) Solitary nodular type (1 case, 7%); (ii) multifocal nodular type (11 cases, 79%); or (iii) diffuse type (2 cases, 14%). The diameter of the lesions ranged from 5 to 105 mm. For the first two types (solitary and multifocal nodular types), the CT findings included low density lesions with clear margins on non-contrast scans, centripetal enhancement in arterial phase, and homogeneous enhancement in the portal venous and delay phases. The findings of non-contrast MRI scans for these two types included low signal intensity on T1-weighted images, heterogeneous high signal intensity on T2-weighted images, and heterogeneous high signal intensity on diffusion-weighted images. The lesions were predominantly located in submarginal areas. On contrast-enhanced MRI, the findings for the first two types included peripheral ring-like enhancement with a central low signal intensity (‘black target-like’ sign) and a central enhanced core surrounded by a low signal intensity halo (‘white target-like’ sign). The findings for the third HEH type (diffuse type) on CT and MRI scans included low density or heterogeneous signal intensity lesions involving regions of part or the whole liver, coalescent lesions (‘strip-like’ sign), and gradual enhancement along central vessels (‘lollipop’ sign). Collectively, these findings indicate that the ‘white target-like’ sign, ‘black target-like’ sign, ‘lollipop’ sign and ‘strip-like’ sign, in addition to capsular contraction and submarginal location, on CT and MRI imaging may have implications for the diagnosis of HEH. Furthermore, a variety of MRI sequences may provide additional information for the differential diagnosis of HEH.