Unusual extrahepatic metastasis to the soft tissue of the left cervical neck area from hepatic epithelioid hemangioendothelioma

A 47-year-old male visited our hospital complaining of fatigue for the past several months. The patient's medical history and a physical examination did not reveal any relevant symptoms. However, a complete blood count revealed a white blood cell count of 16,400/mm (normal = 3.9-9.7). Other laboratory data values were abnormally increased as follows: serum alkaline phosphatase of 295 IU/L (normal = 20-120 IU/L), aspartate aminotransferase of 55 IU/L (normal = 5-40 IU/L), gamma-glutamyl transferase of 318 IU/L (normal = 10-66 IU/L), amylase of 165 (normal = 28-116), and lipase of 78 (normal = 0-60). EHE, epithelioid hemangioendothelioma; MRI, magnetic resonance imaging. Multidetector computed tomography revealed confluent, hypoattenuating nodules, with mild peripheral enhancement, located mainly at the subcapsular portion of the liver. Upon T2-weighted axial magnetic resonance imaging (MRI), the peripheral coalescing nodules had a target appearance with central hyperintensity and a peripheral dark rim (Panel A). A positron emission tomography–computed tomography scan revealed further 2-fluoro-2-deoxy-D-glucose uptake lesions at the left perivertebral space of the infrahyoid neck (Panel B). Subsequently, we performed a neck MRI, which revealed a large, infiltrative, and heterogenously enhanced soft tissue mass in the left perivertebral space (Panel C). An ultrasound-guided biopsy was performed simultaneously at the neck and the liver. The microscopic specimen of the liver was composed of dendritic and epithelioid cells which, with intracytoplasmic lumina, appear as signet ring–like structures. Immunohistochemically, tumor cells are positive for CD34 (clusters of differentiation 34) antigen (Panel D). The obtained soft tissue mass specimen was consistent with metastatic epithelioid hemangioendothelioma (EHE) on microscopic investigation and immunohistochemical testing. Hepatic EHE is a rare, low-grade malignant vascular tumor that occurs exclusively in adults. Clinical manifestation is variable, from asymptomatic patients to patients with hepatic failure, with the most common symptom being pain at the right upper quadrant. Although hepatic EHE is a rapidly progressive disease, prognosis and extrahepatic involvement are more favorable compared with other hepatic malignancies. The most common sites of extrahepatic metastasis are the lungs, peritoneum, lymph nodes, and bones. A general treatment strategy for hepatic EHE has not yet been established. However, the most common treatment is liver transplantation due to the multicentricity of hepatic EHE.1 To the best of our knowledge, the extrahepatic metastasis of hepatic EHE to the soft tissue of the cervical neck area has not been reported previously. Because the imaging characteristics of hepatic EHE might mimic metastatic adenocarcinoma, cholangiocarcinoma, and/or hepatocellular carcinoma, the clinician's awareness of this tendency and a histopathological examination are essential for the accurate diagnosis and proper treatment of hepatic malignancies.2