Congenital bowing of the ulna and aggressive fibromatosis.

The association of skeletal anomalies and aggressive fibromatosis has been documented. Isolated bowing of the ulna is rare, yet its occurrence, particularly in conjunction with congenital dislocation of the radial head, has been documented. This article presents two cases of ulnar bowing in which the patients subsequently developed aggressive fibromatosis. We feel that aggressive fibromatosis may be a latent manifestation of congenital bowing of the ulna. The course of the disease appears to be of an aggressive nature, and patients who present with bowing of the ulna should be followed for the potential development of this disease.