ARRS 2022 Abstracts


E1638. Epithelioid Hemangioendothelioma: Not Simply a Hepatic Pathology
  1. Brian Moloney; Joint Department of Medical Imaging, University of Toronto
  2. Ciara O'Brien; Joint Department of Medical Imaging, University of Toronto
Epithelioid hemangioendothelioma (EHE) is a rare, low-grade, vascular tumor comprising dendritic and endothelial cells with an epithelioid morphology. Clinically, EHE demonstrates clinical behavior intermediate between hemangioma and angiosarcoma. On cross-sectional imaging, EHEs are usually multifocal, heterogeneously enhancing nodules involving both lobes of the liver. Most EHE tumors are encountered in the liver, but they can proliferate in multiple locations throughout the body. Therefore, the radiologist must be aware of the variable extrahepatic presentations, as well as correlative findings, that will aid in the appropriate diagnosis. This exhibit will showcase a spectrum of cases involving extrahepatic EHE and discuss differential diagnoses with imaging pearls for interpretation.

Educational Goals / Teaching Points
The goals of this exhibit are to showcase a spectrum of cases involving extrahepatic EHE, including lung, bone, regional lymph nodes, peritoneum, spleen, and diaphragm; present the variable appearance of EHE at each of these aberrant locations; demonstrate key findings that can lead the radiologist to the appropriate diagnosis; and demonstrate imaging pearls important for clinical management. At the end of this exhibit, the viewer will have increased diagnostic acumen in suspecting extrahepatic EHE.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Key points of this exhibit include demonstrating each of the more common extrahepatic locations with multimodal imaging; identifying key EHE imaging characteristics on MRI and CT for lung, bone, regional lymph nodes, peritoneum, and diaphragm; identifying key sonographic findings of splenic EHE; detailing an appropriate differential diagnosis of lesions with similar appearances to extrahepatic EHE; and discussing unique correlative findings that may aid in diagnosis.

Although generally indolent in clinical activity, EHE has metastatic potential and can demonstrate aggressive behavior. As such, early diagnosis is critical given the lack of approved regimens for the disease once metastatic. The extrahepatic occurrence of this rarity represents a diagnostic challenge; however, the understanding of correlative findings will allow the radiologist to offer a narrower and more accurate differential.