Primary Epithelioid Hemangioendothelioma of the Vertebral Column: A Case Report and Literature Review

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular neoplasm with an incidence of 0.038 per 100,000 inhabitants/year. Primary osseous EHE represents fewer than 1% of all primary malignant bone tumors, and vertebral involvement is exceptionally uncommon. Its variable clinical behavior-ranging from indolent to rapidly aggressive-makes management challenging, especially in the absence of prospective clinical trials. We present the case of a 31-year-old man with progressive dorsolumbar pain of several months' duration. Imaging studies revealed an expansile osteolytic lesion at T11. CT-guided biopsy confirmed the diagnosis of low-grade primary osseous EHE (CD31+, ERG+, 2 mitoses/10 HPF). The patient developed complete spinal cord syndrome while awaiting preoperative embolization, and subsequently underwent posterior hemivertebrectomy with free margins (R0) and T8-L1 instrumented arthrodesis. Six months postoperatively, imaging showed no evidence of residual or recurrent disease. Eight months after surgery, multifocal osseous progression was documented at C6, L2, the right scapula, and multiple ribs. Palliative radiotherapy was administered to symptomatic sites, and pazopanib was initiated as first-line systemic therapy. After four months of treatment, imaging confirmed lesional stability. This case highlights the diagnostic and therapeutic challenges of vertebral EHE in a young patient. Progressive multifocal disease required sequential multimodal management including radical surgery, radiotherapy, and systemic tyrosine kinase inhibition. Lesional stability achieved with pazopanib supports its use as a first-line option in progressive osseous EHE, consistent with current expert consensus.