Sacral osteoblastoma presenting as a L5-S1 disc herniation.

Osteoblastoma is an uncommon neoplasm of the bone accounting for only 0.5-2% of all primary bone tumors. It constitutes 9% of all primary bone tumors arising in the sacrum. The symptoms have a wide spectrum of variety and the diagnosis is often delayed. We report a case of sacral osteoblastoma in a 20-year-old man who presented with classical symptoms of postero-lateral herniation of L5-S1 vertebral disc. The clinical and radiographic findings are discussed as well as the surgical treatment.