[Fibromatosis in children: regression with prolonged chemotherapy. Apropos of 2 cases]

Surgical excision is the usually recommended treatment of Fibromatosis in children. However the invading nature of this tumor is responsible for recurrences leading to mutilating surgery and eventually to death despite the histologically benign appearance. We observed two cases of decrease under lengthy chemotherapy. In the first case, a 4-year-old boy with a huge abdominal wall tumor had two biopsies leading to the diagnosis of fibromatosis. The tumor measured 15 x 14 x 10 cm, and compressed the right ureter when chemotherapy was started. Actinomycin 1,500 microgram/m2 at Day 1 and vincristine 1.5 mg/m2 at Day 1 and Day 8. This courses were repeated every four weeks. Tumor decreased slowly but constantly. After 17 months it measured only 5 cm in diameter. The biopsy confirmed the nonprogressive nature of the residual fibromatosis. In the second case, a 12-year-old boy had a tumor of the left anterior thoracic wall. The histologic study diagnosed a fibromatosis. Two courses of IVA (ifosfamide, vincristine, actinomycin), did not lead to any decrease. A wide excision was achieved but left invaded edges. Then the child was treated by actinomycin 750 microgram/m2 at Day 1 and vincristine 1.5 mg/m2 at Day 1 and Day 8, one course every four weeks during ten months. At this time biopsies revealed a scar without progressive fibromatosis. This two cases show the interest of a chemotherapy in extensive fibromatosis. A mild treatment but for a long time seems to succeed where more intensive courses have failed.