Pediatric angiosarcoma of soft tissue: a rare clinicopathologic entity.

Angiosarcomas are rare tumors that predominantly affect adults and elderly patients. Although angiosarcomas are well described in a variety of clinical settings, they have been poorly studied in children and little is known about their biology, natural history, or optimal treatment. Childhood angiosarcomas are exceedingly rare. The head and neck region and mediastinum seem to be the preferred locations. Most tumors are high-grade tumors. Vasoformative architecture is not always obvious on light microscopy requiring the benefit of immunohistochemical study. The differential diagnosis includes Kaposi sarcoma, epithelioid hemangioendothelioma, hemangiopericytoma, and spindle cell hemangioendothelioma whose prognosis is different. Complete resection is required for patients with localized tumors. Malignant vascular tumors are rare in children in the first 2 decades of life and when they do occur they seem to be more aggressive than in adults. Pathologic diagnosis is difficult particularly in poorly differentiated angiosarcomas requiring immunohistochemical study to confirm vascular differentiation.