Aggressive fibromatosis of the leg and sacrococcygeal region: a report of two cases.

Aggressive fibromatosis is a rare soft tissue tumor that composes of myofibroblasts that arise from musculoaponeurotic structures. It usually affects the abdominal wall but may be also found in other less common sites including the head and neck, submucosa of the oral cavity, spinal, haunch and limbs, especially, the limbs and sacrococcygeal region are rare locations. We described two cases of aggressive fibromatosis. One was 3-year-old girl with aggressive fibromatosis arising from the right leg region. The other was 20-year-old female arising from in the sacrococcygeal region. They were resected with satisfied results. Pathological examination showed that they were composed of fibroblasts, fibrocytes and bundles of collagen fiber. The aggressive fibromatosis, although rare, should be differentiated from some other soft tissue tumors with similar histological features and different localizations of intra-abdominal, abdominal wall and extra-abdominal.