Epithelioid hemangioendotheliomas are rare tumors of vascular origin that usually occur in young adults. In the literature, there are disagreements about the incidence of the most frequently involved organ and tumor. Epelboym et al. stated that the most frequently involved organs were liver, lung and bone, respectively, while in the study of Requena and Kutzner, more than half of the cases were related to vascular structures [2,3]. Epithelioid hemangioendotheliomas are mostly seen in the vascular structures of the venous system (most commonly the femoral vein) [4].

More rarely, it presents as a painful mass lesion originating from arterial vascular structures. It can be confused with aneurysms and arteriovenous malformations as it wraps around the vascular structures in the form of a sheath [5]. Depending on the tumor's occlusion of the vascular structure, findings such as edema and thrombophlebitis may be observed. Distant organ metastases are most common to the lung [4,6]. Fewer cases were reported in the upper extremity arteries than in the lower extremity arteries. Cases of epithelioid hemangioendothelioma seen in the superficial palmar arch, ulnar artery and radial artery have been reported in the literature [7-9].

On ultrasound, it is observed as a hypoechoic mass surrounding the vascular structure to a certain extent, adjacent to the vascular structure. In Doppler ultrasound examination, it is in the form of a mass with vascular blood supply that proves angiogenesis. Venous thrombus can be observed in masses originating from the venous system. Similar to US findings, it is observed as a non-specific soft tissue mass in CT examination. CT angiography can be used to guide surgical excision, evaluate the intraluminal extension of the mass and determine its borders. On MRI, it shows low-to-moderate contrast on T1-weighted images, hyperintense on T2-weighted images, and intense homogeneous enhancement on contrast-enhanced images, also with restriction on diffusion-weighted images. Compared to other imaging methods, MRI is more valuable in evaluating the invasion of the mass into the vascular structure and its relationship with the surrounding structures. On angiography, it is observed as a well-circumscribed dense mass with early venous drainage [1,2]. PET CT can be used to evaluate distant organ metastases. Since there are no typical imaging findings, the diagnosis is always made by pathology. Main treatment is surgery and can be combined with radiotherapy. In surgical treatment, resection of the affected vascular structure and appropriate graft application are performed. Chemotherapy can also be used in metastatic cases. Recently antiangiogenic drugs and monoclonal antibodies have been tested for usability [1,10]. The aim of the treatments is to prevent local recurrences and increase survival. Since it is a rare pathology and there are few case examples in the literature, there is no consensus on its clinical course, imaging findings and treatment.