Diagnostic and Management Options of Osteoblastoma in the Spine

Abstract

BACKGROUND Osteoblastoma is a rare, benign, osteolytic neoplasm commonly found in the spine in early adulthood. Here, we review the clinical characteristics, radiographic findings, and surgical management of patients with spinal osteoblastoma. MATERIAL AND METHODS Thirteen patients with osteoblastoma who underwent surgery at our institute from June 2008 to November 2017 were enrolled in this study. The American Spinal Injury Association (ASIA) impairment scale was used to assess neurological function. All patients were treated with either total excision or intralesional piecemeal excision without postoperative radiotherapy. Clinical efficacy was evaluated by visual analog scale (VAS) scores, the Oswestry Disability Index (ODI) of nerve function, physical and radiographic examinations, bone fusion, and neurologic status. RESULTS The follow-up lasted 23-82 months (average, 43.8 months). The average surgical time was 178.1 minutes (range, 100-230 minutes), with an average intraoperative blood loss of 574 mL (range, 230-1100 mL). Postoperatively, VAS scores decreased from 6.2±1.7 to 0.5±0.7 (P<0.001). The preoperative and final ODI scores were 51.1±7.7 and 22.6±4.9, respectively, reflecting a significant decrease (P<0.001). According to the ASIA classification, 3 patients had grade C, 3 patients had grade D, and 7 patients had grade E disease. Three months postoperatively, 1 patient had grade D and 10 patients had grade E disease; ultimately, all cases were grade E disease. Only 1 patient experienced local recurrence and underwent en bloc marginal resection with postoperative radiotherapy. All patients remained neurologically stable without any major complications. CONCLUSIONS Accurate intraoperative localization with complete resection is the key to preventing recurrence. Aggressive surgical resection can achieve satisfactory clinical and radiographic outcomes.

Figure 1

A case with T1 osteoblastoma localized in the right vertebral body and pedicle. Preoperative sagittal (A) and axial (B) CT scans demonstrate an expansile lesion with peripheral hardening of bony destruction of right vertebral body (white arrow). Preoperative (C) sagittal short time inversion recovery (STIR) sequence image and (D) sagittal-axial T2-weighted image showing that the paraspinal soft tissue mass exhibited high signal intensity with the T2WI and STIR sequences, indicating spinal cord compression (white arrow). (E) Intraoperative photo showing that the localization of lesion was performed. (F, G) Intraoperative photo showing that the tumor was completely removed (white arrow). (H) Intraoperative removal of specimens. (I) Photomicrograph of the specimen revealing a dense osteoid matrix and plump osteoblasts with new osteoid, suggesting osteoblastoma (hematoxylin and eosin, original magnification 100×). (J, K) Lateral radiographs of the cervical vertebrae at the 43-month follow-up showing C7–T2 stabilization without tumor recurrence.

Figure 2

A case with T1 osteoblastoma localized in the left laminae. Preoperative axial (A), coronal (B) and sagittal (C) CT scans demonstrate an expansile lesion with peripheral hardening of bony destruction of left laminae (white arrow). Preoperative (D) sagittal T1-weighted image and (E) sagittal T2-weighted image showing that the paraspinal soft tissue mass exhibited high signal intensity with the T2WI and intermediate signal intensity with the T1WI sequence, indicating spinal cord compression. (F) Axial T2-weighted image and (G) axial STIR sequence image showing a single cystic lesion with cortical destruction at the posterior elements of the T1 vertebra and slight edema of the surrounding soft tissues. The lesion exhibited a hyperintense signal with the STIR sequence and a heterogeneously hypointense signal with the T2WI sequence (white arrow). (H) Intraoperative photo showing that the lesion was removed. (I) Intraoperative removal of specimens. (J) Postoperative pathological examination revealed that the stroma was composed of fibrovascular connective tissue. Plump osteoblasts with new osteoid and anastomosing trabeculae of woven bone suggesting osteoblastoma. (hematoxylin and eosin, original magnification 100×).