Metachronous osteoid osteoma of the mid diaphysis and proximal metaphysis of the tibia: double localization at 5 years interval

Osteoid osteoma (OO) is a benign osteoblastic tumor occurring frequently during growth. Treatment is based on mininvasive techniques such as radiofrequency ablation, microwave ablation or cryoablation, nowadays preferred to surgical or arthroscopic excision. The disease may recur, mainly owing to incomplete tumor excision or ablation. A girl aged 6 years presented with non-specific left anterior leg pain that had persisted for two weeks. OO of the left tibia at the level of mid-diaphysis was diagnosed, and surgical excision and curettage were performed. After five years the patient started complaining of pain at the proximal left tibia, with clinical characteristics similar to the earlier instance. Radiological findings were compatible with a new-onset OO. The patient underwent surgical excision of the tumor followed by bone grafting, resuming full daily activities after 18 months. We report an unusual case of double localization of pediatric osteoid osteoma of the tibia at five years interval. Further studies may establish a systemic etiology and associated morbidities.