A rare occurrence of osteoblastoma in a child.

To report a rare occurrence of osteoblastoma involving the L4 vertebra in an 8-year-old female child with histological features suggestive of osteoblastoma with secondary aneurysmal changes. The mean age incidence of osteoblastoma is 20.4 years. In our case, a rare presentation of osteoblastoma was seen in the first decade. The child was admitted with a 1-year history of increasing back pain and radiculopathy. The child was evaluated with X-rays, computed tomography scan and magnetic resonance imaging, which indicated involvement of the posterior elements of the 4(th) lumbar vertebrae. Decompression of the L5 nerve and resection of the tumor was performed. Osteoblastoma is a rare tumor with an incidence of 1% of all tumors and 30-40% of cases involving the spine. Osteoblastoma occurs most commonly in males (M:F, 2.5:1). The most common area of involvement is the cervical spine followed by the lumbar spine. Posterior elements of the vertebrae are commonly involved.