CASE 16804 Published on 26.06.2020

Hepatic epithelioid hemangioendothelioma

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Ana Margarida Alves, João Louro, Raquel Maia, Manuela França

Department of Radiology, Centro Hospitalar e Universitário do Porto, Porto

Patient

41 years, female

Categories
Area of Interest Liver ; Imaging Technique MR
Clinical History

41-years-old woman with history of deep vein thrombosis performed a CT angiography, which incidentally identifies multiple hepatic nodules. The patient had been taking oral contraceptives for 17 years. Liver viral serology and tumour markers were negative. Liver MRI was performed for further characterisation of the hepatic nodules.

Imaging Findings

On CT angiography, well-circumscribed hypoattenuating hepatic nodules were seen, predominantly at the liver periphery. After intravenous contrast administration, those nodules revealed slow peripheral enhancement and the “lollipop sign” was recognised (Fig. 1). On MRI, those lesions were hyperintense on T2-WI, some of them with a target-like pattern (Fig. 2a), and hypointense on T1-WI. The periphery of the nodules exhibited increased signal intensity on high b-value DWI and decreased signal intensity on the ADC map (Fig. 2b). On contrast-enhanced dynamic examination, the lesions demonstrated slow progressive, peripheral ring-like enhancement (Fig. 2c-h). Some of the enhanced lesions were surrounded by a thin and hypointense halo on the venous phase (‘black target-like’ sign) (Fig. 2g) and were associated with capsular retraction (Fig. 2f-h). The imaging findings suggested the diagnosis of hepatic epithelioid haemangioendothelioma, which was confirmed by ultrasound-guided biopsy. The patient was referred for hepatic transplantation.

Discussion

Hepatic epithelioid hemangioendothelioma (HEH) is a rare neoplasm of vascular origin, with low- to intermediate-grade malignant potential. It usually affects women between 30-40 years of age. Its aetiology is unknown, however, the association with oral contraceptives have been suggested.

The clinical manifestations are nonspecific and include right upper quadrant pain, hepatomegaly and weight loss. Its detection is frequently incidental in an asymptomatic patient [1].

HEH may present in two forms: on an early stage, usually there are multiple nodules in peripheral distribution (nodular pattern) and then, later, the lesions may increase in size and coalesce (diffuse pattern) [2].

Ultrasound usually shows peripherally hepatic lesions that are predominantly hypoechoic but can also show heterogeneous echogenicity.
CT findings indicative of EHE include multiple hypoattenuating nodular lesions in a peripheral location of both hepatic lobes [3].
On contrast-enhanced CT images, the tumour enhancement usually has a target-like or halo appearance that results from a nonenhanced outer rim of avascular tissue, an enhanced inner peripheral rim, and a central area that may be enhanced or nonenhanced at delayed imaging [4]. Other CT findings include capsular retraction in some subcapsular lesions, the presence of calcifications and the “lollipop sign”, that represents a hepatic/portal vein or their tributaries/branches tapering and terminating at the edge of these lesions [3, 5].

On MRI, the lesions appear hypointense on T1-WI and, on T2-WI, they usually have a target-like appearance: the moderately hyperintense signal corresponding to the viable tumour, and the central markedly hyperintense area reflecting necrosis and edematous connective tissue. After contrast administration, the target pattern is similar to contrast-enhanced CT images [3,4].

The target appearance can also be appreciated on diffusion weighted images and ADC maps, with restricted diffusion of the peripheral regions that have viable and hypercellular tumoral tissue. Mean ADC values were found to be higher in comparison with other hepatic tumours [4].

A biopsy is required for a definitive diagnosis of HEH [6].

The clinical course of HEH is variable. In spite of the possibility of hepatic failure and extra-hepatic metastasis, the prognosis is considered better than other hepatic malignancies. Treatment includes orthotopic liver transplantation (even with metastatic disease), surgical resection and chemotherapy or radiotherapy [1].

The diagnosis of HEH should be considered when there are predominantly peripheral or diffuse nodular hepatic lesions, particularly when associated with the target-like appearance and “lollipop sign” on contrast-enhanced CT or MRI, and normal serological tumours markers.

Differential Diagnosis List
Multifocal hepatic epithelioid hemangioendothelioma
Liver metastasis
Hepatic lymphoma
Intrahepatic multifocal cholangiocarcinoma
Hepatic hemangiomas
Final Diagnosis
Multifocal hepatic epithelioid hemangioendothelioma
Case information
URL: https://www.eurorad.org/case/16804
DOI: 10.35100/eurorad/case.16804
ISSN: 1563-4086
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