After Dail
et al. first identified PEH in 1975 [
1], in 1982 Weiss and Enzinger used the term
epithelioid hemangioendothelioma to describe a vascular bone and soft-tissue tumor with intermediate malignancy between hemangioma and angiosarcoma [
2]. Weldon-Linne
et al. discovered a factor VIII–related antigen in malignant cells, confirming their endothelial origin [
3]. The median age of onset is 36 years (range, 20 to 60 years) [
6]. The most common presentations are liver alone (21%), liver plus lung (18%), lung alone (12%) and bone alone (14%) [
7]. Approximately 50% to 76% of patients are asymptomatic. Some present with chest pain, pleuritic pain, cough, dyspnea, malaise [
8], hemoptysis and anemia. Bone metastases cause pain and swelling in the affected area, pathological fractures [
9], spine compression if the lesions arise in vertebrae, which result in paresthesia, loss of muscular strength and paraplegia [
10]. Hematologic and gastrointestinal disease, as well as weakness or numbness, may also occur because of EHE dissemination [
7]. Radiologically, PEH consists of multiple bilateral perivascular nodular opacities with a diameter ≤1cm [
10], and sometimes present with lymph node metastases, pleural thickening or ground-glass opacities. Bone metastases appear as osteolytic lesions with homogeneous contrast enhancement, cortical disruption and soft-tissue swelling [
9]. Histologically, the tumor has a micropolypoid growth, and tumor cells with cytoplasmic vacuoles occasionally contain erythrocytes [
11] expressing Fli-1 and CD31 [
12], which are relatively specific endothelial markers. The overall survival rate of EHE patients is better when the disease is localized (90% at 1 year and 73% at 5 years) than when there is multi-organ progression (53% at 1 year and 24% and 5 years) [
7].
Because of the radiobiological characteristics of PEH (slow growth), RT is ineffective. Good local control has been reported in a patient with exclusive EHE bone presentation treated by combining RT with bone surgery [
14]. From the time EHE was correctly defined, several research groups have studied irradiation for EHE. A protocol of 4,000cGy for 4 weeks [
13], followed by a 3,000cGy course of RT to the spine after surgical removal of EHE of the vertebrae [
15] has been described. In the study reported by Aquilina
et al., one patient survived for 11 years, but the other patients experienced worsening conditions due to multiple hepatic and abdominal metastases. Authors of another report described adjuvant RT delivered at dose of 6,400cGy to treat axillary EHE, which resulted in the absence of lymph node metastases but widespread pleuropulmonary metastasis [
6]. Local irradiation after bone EHE resection at 6,000cGy in 23 fractions for 43 days showed good tolerance, without regional or distant metastases or local recurrence at 6-, 12- and 24-month follow-up examinations [
10]. A recently reported protocol of 33 radiation fractions totaling 5,940cGy was applied to treat residual mastoid EHE. The authors found that imaging performed 8 years after surgery and RT revealed neither recurrence nor any change in the patient’s clinical status [
16].