Aneursymal Bone Cyst Causing a Femoral Neck Fracture: A Pediatric Case

Aneurysmal bone cysts are benign active or aggressive bone lesions that commonly arise in the long bones, especially the femur, tibia and humerus and in the posterior elements of the spine. They are extremely rare, occurring in 1.5 per one million people per year. They most commonly occur in the metaphysis of long bones during the first two decades of life and usually present with pain, swelling or fracture. The etiology of aneursymal bone cysts is unknown, but numerous authors have proposed that they form in response to vascular disruption in the bone due to a pre-existing primary tumor or a traumatic insult. The early rate of growth of aneursymal bone cysts is also unknown. We wanted to share this case to show the destructive effects of aneursymal bone cysts.