Osteoblastoma in the sacrum: a case report

Osteoblastoma is a rare primary neoplasm of bone, usually categorized as benign bone tumor. It accounts for about 1% of primary bone tumors. Roughly 40 % of osteoblastomas localize to the spine which may cause pain, scoliosis, or even neurologic deficit. Involvement of the sacrum by osteoblastoma is rare. We report a case of osteo blastoma in the sacrum with good result after treatment. A 13-year-old male presented with a 6- month history of low back pain radiating from the right buttock to the right leg. Plain radiography, CT, and MR I of the lumbosacral spine revealed a lesion over the right ala of the sacrum. Biopsy confirmed a diagnosis of osteoblastoma. Superselective transarterial embolization was done before surgery to minimize bleeding. After sur gery, his back pain improved, and was recur rence-free at the time of 3-year follow-up after treatment. Osteoblastoma is a rare benign primary neo plasm of bone, which shows a 2:1 predilection for males [1] between the ages of 30 and 60 years [2]. It is a vascular osteoid or bone-forming tumor with abundant osteoblastoma cells, and it accounts for about 1% of primar y bone t umors in the United States. The sacrum, in particular, is a rare location for osteoblastoma, as only 9% of primary sacral tumors are diagnosed as osteoblastoma [3]. Tumors in the sacrum can cause back pain, scoliosis, and neurological symptoms [4]. There are several controversies in the litera ture relating to osteoblastoma. One issue is that the distinction between osteoblastoma and osteoblastic osteosarcoma can be difficult [5]. Another issue is that the local recurrence rate has been reported to be as low as 10% [6] or as high as 67% [7], which may be related to the difficulty of differentiating osteo blastoma from osteosarcoma.