Infantile hemangiopericytoma--case report and literature review

Infantile hemangiopericytoma is a rare soft tissue neoplasm of pericytic origin and is almost always benign, despite its worrisome pathologic features. We describe a 2-month-old male infant with a soft tissue mass on his right thigh. Histologically, the lesion showed a characteristic hemangiopericytoma-like vascular pattern, multilobulation, and moderate mitotic activity. These morphologic features were prediagnosed as infantile hemangiopericytoma. However, immunohistochemical and ultrastructural studies revealed a heterogeneous cellular composition, primarily pericytes and endothelial cells, similar to that observed in infantile myofibromatosis.