Successful treatment of an infant with constitutional chromosomal abnormality and hemangiopericytoma with chemotherapy alone.

Hemangiopericytoma is a rare vascular tumor, of which 5% to 10% occur in the pediatric population. Although usually benign in infants, local recurrence, metastasis, and deaths have been reported. Clonal chromosomal rearrangements have been described, most involving the long arm of chromosome 12. We report a case of a 6-month-old boy with an hemangiopericytoma of the left forearm initially incorrectly diagnosed as hemangioma. He was treated successfully with chemotherapy alone using vincristine, doxorubicin, actinomycin-D, and cyclophosphamide. Although cytogenetic analysis was not performed on his biopsy, it was later discovered that a prenatal karyotype had shown 46,XY,inv(12)(q15q24.1).