Total en bloc spondylectomy in the treatment of aggressive osteoblastoma of the thoracic spine.

Osteoblastoma is an uncommon, benign osteoblastic tumor accounting for <1% of all primary bone tumors. Aggressive osteoblastoma is a variant of osteoblastoma and is considered to be a borderline or intermediate osteoblastic tumor, first defined by Dorfman and Weiss in 1984. As a rare tumor, its true incidence and distribution are not clearly known. Treatment of osteoblastoma is complete surgical excision by either curettage or en bloc technique. Recurrence is seen in 10% to 15% of cases, and aggressive osteoblastoma are more likely to recur (<or=50%). Transformation to osteosarcoma has been reported, and this rare phenomenon is typically seen in the setting of multiple recurrences. Therefore, total en bloc spondylectomy constitutes the treatment of choice for recurrent aggressive osteoblastoma. This article reports a rare case of recurrent aggressive osteoblastoma of the thoracic spine, successfully treated by total en bloc spondylectomy. Treatment options for such a highly recurrent benign tumor are discussed.