Hemangiopericytomas (HPC) are malignant vascular tumors arising from mesenchymal cells with pericytic differentiation. HPC immumnohistochemical profile is uncertain and diagnosis is usually controversial. Differential diagnosis from synovial sarcoma, mesenchymal chondrosarcoma, fibrous histiocytoma, and solitary fibrous tumor is a major medical challenge. The existence of this particular disease type is even sometimes questioned, and systematic review of pathological slides is essential. Two subtypes of hemangiopericytomas have been described: infantile HPC in infants under 1 year, and adult disease in children over 1 year and adults. HPC is a rare tumor of adult life (fifth decade) and pediatric cases account for approximately 3% of all soft tissue sarcomas in this age group. These tumors usually develop in the limbs, the pelvis, or the head and neck, and mostly in muscle tissue. Surgery remains the mainstay treatment. However, prognosis being usually favorable, the use of mutilating surgical procedures should be restrained. Adjuvant chemotherapy is an option in case of unresectable, life-threatening tumors, particularly in the infantile subtype. Adjuvant radiation therapy is appropriate for patients with high grade tumors or incomplete resections. Late relapses may occur and require long-term follow-up. Cytogenetic abnormalities (translocations) have been found in some hemangiopericytomas.
Last update: April 2004