Unicameral bone cysts in the humerus and femur in the same child.

Although simple bone cysts in children have been described by many authors, there has been only one previous report of more than one lesion in a single patient. We describe an 11-year-old boy with symptoms caused by a cyst in the proximal femur. Following steroid injection of the cyst, a pathological fracture occurred and was treated by immobilization in a cast. A year later, a pathological fracture occurred through a cyst in the proximal humerus. This was treated in a sling. Steroid injection of both lesions was performed when the cystic areas persisted, and both cysts subsequently healed. This case demonstrates that simple bone cysts are not always solitary lesions and that patients with these cysts should be carefully monitored for recurrence following treatment.