epithelioid hemangioendothelioma


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  • Clinical

    • site: extremities
    • prognosis: between hemangioma and angiosarcoma
  • Histology

    • most originate from a vessel, usually small vein, showing intraluminal growth
    • cytology: round to slightly spindle pink endothelial cells, cytoplasmic vacuoles containing RBCs
    • can have metaplastic bone with oscteoclastic giant cells
    • malignant features: nucleat atypia, mitosis > 1 per 10 hpf, spindle cells, necrosis
  • Stains

    • positive: CD31, CD34
    • 25% have focal CK
  • Ddx