Multiple Primary Aneurysmal Bone Cysts: A Case Report and Literature Review.

Herein, we report the case of a 12-year-old boy diagnosed with multiple aneurysmal bone cysts (ABCs) who had previously undergone surgery on the proximal left tibia, proximal left femur, and distal tibia. During follow-up after the surgery, he developed another lesion on the proximal left humerus. Although rare, the pathological diagnosis was multiple ABCs.