Aneurysmal bone cysts in young children.

We reviewed seven young children (< or = 10 years) with aneurysmal bone cysts. There were four girls and three boys. Six had involvement of the long bones and one had involvement of the clavicle. The average age was 5.5 years (range 2.9-10.6 years). Initial treatment was curettage and bone grafting. There were recurrences in five of the seven children (71%). This represented 100% of children with radiographically aggressive or active lesions. The recurrences appeared rapidly, at an average of 8 months from the first procedure. The mitotic index of the initial lesion did not correlate with that of the recurrent lesion. Surgical management of the recurrences must be handled individually, but repeat curettage and grafting is only recommended when surgical resection is not possible. This high rate of recurrence in radiographically aggressive or active aneurysmal bone cysts in young children should be considered when planning treatment, and in the preoperative counseling of parents.