Epithelioid hemangioendothelioma, light micrograph. Epithelioid hemangioendothelioma is an uncommon vascular tumour, of intermediate malignancy between entirely benign (non-cancerous) hemangiomas and highly malignant (cancerous) angiosarcomas. It is composed of cords, strands, and solid aggregates of round, oval, and polygonal cells, with abundant pale eosinophilic cytoplasm, vesicular nuclei, and inconspicuous nucleoli, embedded in a fibromyxoid or sclerotic stroma.