Aggressive fibromatosis. Report of two cases with rare clinicopathological manifestations.

Two cases of aggressive fibromatosis are described, one with tricentric origin and with the first tumor originating in the hand, the other with malignant transformation into a myxoid fibrosarcoma, grade III. The primary treatment of aggressive fibromatosis should be wide excision, and the follow-up should be long, taking into account the possibility of multicentricity and the risk of malignant transformation.