Clinical characteristics of Japanese patients with epithelioid hemangioendothelioma: a multicenter retrospective study

BackgroundEpithelioid hemangioendothelioma is an exceedingly rare sarcoma often occurring as an indolent angiocentric vascular tumor at various anatomic sites. Few reports have evaluated large case series of epithelioid hemangioendothelioma.MethodsWe conducted a retrospective analysis of the clinical data of 42 consecutive patients with epithelioid hemangioendothelioma who were pathologically diagnosed between 1990 and 2014 at 13 Japanese tertiary hospitals. We analyzed their clinical characteristics, tumor features and prognostic factors.ResultsThe study included 22 men and 20 women, with a median age of 54 (range, 18-78) years. Pain was the most common symptom, occurring in 15 (68%) of the 22 symptomatic patients. The median maximum tumor diameter was 4.0 (range, 1.0-12.8) cm. The most commonly involved organs were the liver (81%), lungs (57%), and bones (12%). The overall survival rates were 79.5% at 1year and 72.0% at 5years. Substantially better survival was observed in asymptomatic patients than in symptomatic patients (P=0.03), and better survival was also ovserved in patients with Ki-67 index 10% than in those with Ki-67 index >10% (P=0.04). By multivariate analysis, tumor size >3.0cm was associated with decreased survival (P=0.049, hazard ratio 13.33).ConclusionsThis study showed the clinical characteristics of Japanese patients with epithelioid hemangioendothelioma. Tumor size >3.0cm is an independent indicator of a poor prognosis in epithelioid hemangioendothelioma. The presence of symptoms at the time of diagnosis and high Ki-67 index implied poor survival.