Congenital hemangiopericytoma. An ultrastructural, immunocytochemical, and flow cytometric study.

Congenital (infantile) hemangiopericytoma is a rare soft-tissue tumor that has been described as a distinct subtype of the classic hemangiopericytoma. We report the ultrastructural, immunocytochemical, and flow cytometric features of a case diagnosed in a male neonate 3 days after birth. The tumor appeared structurally similar to its adult counterpart, meriting the designation hemangiopericytoma, but the improved prognosis that has been reported in young children supports according the infantile form the status of an entity rather than merging it with its adult counterpart.