Treatment of extra-abdominal aggressive fibromatosis with pegylated interferon

Aggressive fibromatosis (desmoid tumor) is a very rare neoplasm arising from the musculoaponeurotic structures. It is characterized by locally aggressive growth, and a tendency to relapse but not to metastasize. We report on a young woman with a large desmoid tumor of the left foot. Multiple operations and radiotherapy had resulted in local recurrences. Long-term immunointervention with pegylated interferon alfa-2b, however, led to marked clinical improvement of the patient's condition and a radiologically proven stabilization of the disease.