Hepatic Epithelioid Hemangioendothelioma

Abstract

Epithelioid hemangioendothelioma is a rare vascular tumor, composed of epithelioid and histiocytoid vascular endothelial cells in myxoid or fibrotic stroma, which can arise in multiple locations throughout the body. In the liver, this neoplasm usually presents on imaging as an incidental finding of multifocal, heterogeneously enhancing nodules in both lobes or presents clinically with nonspecific abdominal symptoms. Histologically, the tumor has been mistaken for metastatic carcinoma, angiosarcoma, hepatocellular carcinoma, and cholangiocarcinoma. The neoplasm usually stains positive for vascular markers, such as factor VIII–related antigen, CD31, and CD34, and negative for cytokeratins. The translocation t(1;3)(p36.3;q25), resulting in the CAMTA1-WWTR1 fusion product, is the most commonly identified genetic abnormality with this tumor. Although hepatic epithelioid hemangioendothelioma can have a varied clinical course, it is generally considered less aggressive than angiosarcoma. There is no consensus treatment protocol and techniques including liver transplantation, liver resection, chemotherapy and/or radiation therapy, and surveillance have all been used with varying outcomes.