An osteoid osteoma is a benign bone-forming (osteoblastic) tumor most often arising in long bones of adolescents, usually in the lower extremities (femur, tibia) and spine, but sometimes elsewhere, such as in the hand, shoulder, ribs, or neck. Osteoid osteoma is more common in males.

Osteoid osteoma is characterized by the appearance of a distinct radiolucent nidus, believed to be prostaglandin-producing, amid spongy diffuse sclerotic bone. Signs and symptoms include pain not associated with physical activity or exercise, often nocturnal and described as aching pain. They also include swelling, tenderness, and bone deformity.

Other signs and symptoms depend on the location of the osteoid osteoma and can include limited range of motion, limping, leg-length discrepancy, scoliosis, muscle atrophy, contracture, or spasm.

Management focuses on relief of pain and inflammation with nonsteroidal anti-inflammatory medication and watchful monitoring of signs and symptoms. Prognosis is good, since eventually osteoid osteoma self-resolves.

For more severe symptoms, treatment choice depends on tumor location, extent of bone lesions, and availability of therapies. These include resection, percutaneous radiofrequency, laser thermal ablation, and more recently, focused ultrasound therapy. Complete removal of the nidus prevents recurrence.

Related topic: osteoma