a 24-year - old woman was referred to chonnam national university hwasun hospital with a palpable nodule in the left side of her neck . a nodule had appeared on the site where she had undergone a left thyroidectomy for nodular hyperplasia two years previously . on physical examination , the nodule was found to be hard and painful when pressure was applied , and intermittent swelling of the left upper limb was noted , leading to suspicion of a chronically occluded left subclavian vein . a chest computed tomography ( ct ) scan showed a 3-cm mass - like lesion in the left supraclavicular area with suspected internal jugular vein invasion ( fig . the diagnosis of the nodule as suspicious for metastatic carcinoma was made by sonography - guided fine needle aspiration cytology . further testing , including positron emission tomography ( pet)/ct , was performed on the assumption that the nodule reflected lymph node metastasis from an unknown primary site . we then planned the surgical excision of the tumor in order to make a definitive histological diagnosis , in accordance with the patient s desire to remove the tumor . the neck was extended in the supine position , and a left collar incision was performed . contrary to our expectations , a tumor was found that arose from the internal jugular vein . the incision was extended medially and laterally in order to define the tumor boundaries and adjacent vasculature . after the identification of a chronic innominate vein occlusion , the tumor was resected en bloc with the involved veins following ligation of the innominate , left internal jugular , and left subclavian veins . the patient s postoperative course was uneventful and no swelling of the left upper limb was observed . histopathologically , the tumor was found to be composed of cords and nests of spindled epithelioid cells with intra - cytoplasmic vacuoles in a hyalinized stroma . these histopathological and immunohistochemical findings were compatible with the diagnosis of an epithelioid hemangioendothelioma ( ehe ) . the patient was referred to the hematology department for adjuvant radiotherapy in order to ensure for better local control , and received a total dose of 60 gy . over the course of 18 months of follow - up , she has remained in good condition , with no evidence of local recurrence or distant metastasis . hemangioendothelioma ( he ) refers to a group of vascular neoplasms involving the skin and soft tissues , and is sub - classified into six categories : papillary intralymphatic angioendothelioma ( dabska tumor ) , retiform he , kaposiform he , epithelioid he , pseudomyogenic he ( epithelioid sarcoma - like he ) , and composite he . each of these neoplasms shows characteristic histopathological features . according to the current world health organization histological classification published in 2002 an angiocentric vascular tumor with metastatic potential , composed of epithelioid endothelial cells arranged in short cords and nests set in a distinctive myxohyaline stroma. ehe develops in either superficial or deep soft tissues such as the skin , liver , lung , or the extremities . although ehe usually originates from a vessel , it is relatively rare for primary vascular ehe to originate from a large vein or artery , is relatively rare . a few recent reports have described intravascular ehes arising from large vessels such as the inferior vena cava   and azygos vein . most ehes are asymptomatic , although edema or thrombophlebitis can develop due to their vascular origin . in most cases that have been described , the diagnosis was based on postoperative histological findings , because no specific radiological features led to the suspicion of ehe . in our case , the tumor was first suspected to be metastatic lymphadenopathy with an unknown primary site based on pre - operative radiological findings and fine - needle aspiration cytology , whereas intraoperative findings indicated that the tumor originated in the left internal jugular vein . typical histological findings include nests and cords of epithelioid endothelial cells distributed in a myxohyaline stroma and the presence of intracytoplasmic lumina ( vacuoles ) . the tumor cells can be confirmed by immunohistological studies , in which cd31 , cd 34 , fli1 , and vimentin are the most commonly used markers . surgical resection is the preferred treatment modality , and chemotherapy or radiotherapy can be deployed as adjuvant therapies for highly aggressive ehe . although the majority of ehes show an indolent clinical course , metastasis ( 20%30% ) and death ( 10%20% ) have been reported in the literature . described the histological and clinical features of 49 cases of ehe that originated in the soft tissue . the overall five - year disease - specific survival rate was 81% , and the metastasis rate was 22% . they suggested that ehe can be classified into two risk groups , with markedly different clinical courses depending on mitotic activity and tumor size . in summary , we have reported a case of epithelioid he arising from the left internal jugular vein that was pre - operatively misdiagnosed as metastatic lymphadenopathy with an unknown primary site .
epithelioid hemangioendothelioma ( ehe ) is a relatively rare and moderately aggressive type of vascular tumor . 
 we describe a case of ehe that presented in a 24-year - old woman as a palpable nodule in the left cervical area . radiological examinations and 
 fine - needle aspiration cytology led to a preliminary diagnosis of metastatic lymphadenopathy with an unknown primary site . 
 however , during surgery , we determined that the nodule was an intra - vascular tumor arising from the left internal jugular vein . 
 the histopathological examination revealed cords of epithelioid endothelial cells distributed in a hyaline stroma , compatible with a diagnosis of ehe .