CT fluoroscopy-guided radiofrequency ablation of osteoid osteoma with double nidi.

Osteoid osteoma (OO) is a common benign bone tumor, usually found in children and young adults. Fewer than 30 cases of multicentric OO in a single bone have been reported in the world literature. We present the case of a 17-year-old boy with OO in the left tibia, containing double nidi. Plain radiography and computed tomography (CT) revealed two adjacent nidi surrounded by bony sclerosis within the distal left tibia. The tumor was successfully treated using two separate CT fluoroscopy-guided percutaneous radiofrequency ablations during a single session. The patient achieved complete pain relief the next day, and has remained asymptomatic for 9 months since treatment.