An aggressive aneurysmal bone cyst of the proximal humerus and related complications in a pediatric patient.

Clinical behavior of aneurysmal bone cyst (ABC) in younger patients can be more aggressive than that in older children and adults. Angular deformity and shortening can occur due to growth plate destruction or tumor resection. A 11-year-old boy who had been operated twice in another center for an ABC located in the left proximal humerus presented to the author's institution with complaints of pain, deformity and shortening of the left arm.