Infantile fibrosarcoma: clinical and histologic responses to cytotoxic chemotherapy

Infantile fibrosarcoma (IF) is a rare soft tissue sarcoma that presents either at birth or in the first year of life. Complete surgical resection is usually curative but chemotherapy may shrink the tumor to facilitate complete resection. This report describes the histologic changes and outcomes in four patients with IF treated with chemotherapy and surgical resection.

A retrospective review was performed of patients treated between 2000 and 2007.

All four patients are alive with excellent functional outcomes. The patients were diagnosed from birth up to 7 months of age; three had lower extremity tumors and one had a neck tumor. All patients received vincristine, cyclophosphamide, and actinomycin; one patient also received ifosfamide and etoposide after tumor progression. One tumor, arising from the neck, had rapid shrinkage. Two lower extremity tumors had only modest changes in dimensions but upon resection, the tumor bed contained fibrous tissue with exaggerated small caliber vessels. The fourth infant developed metastatic lesions in the central nervous system, orbits, lungs, and kidney after complete removal of the primary tumor. The metastatic lesions responded to chemotherapy and have remained stable for over 3 years.

IF is a chemosensitive tumor. In patients where a clinical response is not apparent, cytoreduction of the tumor and replacement with fibrotic and fibrovascular tissue may facilitate gross-total resection. The chemotherapy-responsiveness of this tumor may abrogate unfavorable features such as metastatic or residual tumor.