Presentation
Gradual onset of intermittent abdominal pain since 1 year.
Patient Data
Contrast enhanced US- delayed
The non-contrast ultrasound images demonstrate multiple mixed echotextures and predominantly hypoechoic lesions distributed peripherally throughout the liver. Few of them demonstrate early arterial phase enhancement and marginal filling with predominantly hypoechoic on delayed post-contrast images.
The surgical pathology confirmed this case to be epithelioid hemangioendothelioma.
Case Discussion
Hepatic epithelioid hemangioendothelioma (HEHE) is a rare, indolent malignant vascular tumor that affects a younger population, with a peak incidence in 30–40 years 1,2. US imaging findings are variable depending on size and the presence of fibrosis 6. Nodules can be single or multiple, even confluent. Hypoechoic lesions are more common however the lesions may have a hyperechoic or isoechoic appearance relative to liver parenchyma 3.
Contrast-enhanced ultrasound (CEUS) is used to differentiate focal liver lesions without the risk of nephrotoxicity or radiation. CEUS can be used to clarify indeterminate CT and MR appearances; it has the advantage of continuous evaluation, meaning that critical findings are not missed due to suboptimal timing. Microbubbles used in CEUS are purely intravascular and this avoids the confusion that can occur due to the mixed intra- and extravascular distribution of CT or MR contrast agents 4.
Although the lollipop sign, capsular retraction, and target sign on more than one sequence are relatively specific signs for larger lesions on MR imaging, CEUS can help differentiate smaller lesions of HEHE from benign hemangiomas 5: washout on CEUS favors malignancy 4.
Ultimately, the diagnosis depends on unique immunohistochemical findings.