CT-guided Percutaneous Radiofrequency Ablation of Osteoid Osteoma with Double Nidi in One Session

Osteoid osteoma with multiple nidi is a rare condition. The aim of this report is to share a case of an osteoid osteoma with two separate nidi, which underwent radio-frequency ablation (RFA) treatment under CT-guidance for each of the nidi in the same session. A 15-year girl with osteoid osteoma in left tibia was referred to our clinic for percutaneous RFA. She had pain that worsened at nights. The patient was diagnosed as osteoidosteoma, according to radiologic findings and the clinical symptoms. After CT-guided percutaneous RFA of each nidi in the same procedure, pain was relieved in 24 hours. Each of the RFA-treatments was successful in pain control without any complications and no recurrence occurred during eight months of follow-up period. To our knowledge, this case is one of the very few cases with double nidi, which was treated with RFA in one session. RFA is safe in treatment of osteoid osteomas; even two close and separate nidi can safely be treated in the same session. Key Words: Osteoid osteoma, Nidi, Treatment, Radiofrequency ablation.