Clinical characteristics and treatment options for two types of osteoblastoma in the mobile spine: a retrospective study of 32 cases and outcomes

Abstract

Purpose A retrospective study of 32 patients with osteoblastoma (OBL) in the mobile spine was performed to analyze the clinical characteristics of two types of spinal OBL. We also aimed to find influential factors for OBL in the mobile spine. Methods Between 2002 and 2011, 32 patients with either conventional osteoblastoma (CO) or aggressive osteoblastoma (AO) in the mobile spine were treated in our center. All patients were treated with either total excision or subtotal excision ? postoperative radiotherapy. The mean follow-up was 45.8 (18-128) months. Clinical data and surgery efficacy were analyzed to search for clinical characteristics of two subtypes of spinal OBL and discuss the possible factors influencing relapse. Results There is significant difference between CO and AO in tumor size (p \ 0.0005), preoperative alkaline phosphatase (ALP, p \ 0.0005) and intraoperative blood loss (p = 0.013). Multivariate logistic regression was used to find the influential factors for relapse and the results were: preoperative ALP, b = 0.023, p = 0.029; surgery protocol, b = -7.597, p = 0.007; tumor size, C3/\3, b = 24.805, p \ 0.0005; age, b = 0.054, p = 0.632; and pathology type, b = 1.998, p = 0.34. Conclusions Tumor size, preoperative ALP and CT images were helpful for distinguishing AO from CO. The difference in intraoperative blood loss between CO and AO is mainly attributed to the size of the lesion. Preoperative ALP, surgery protocol and tumor size (C3/\3) were considered to significantly influence relapse of spinal OBL.

Osteoblastomas of the spine: a comprehensive review

“…65 In 1 series comparing conventional osteoblastomas with aggressive osteoblastomas, it was found that the mean duration of symptoms overall was approximately 16.2 months in patients with conventional osteoblastomas, whereas patients with the more aggressive variant tended to present almost 1 year earlier. 101 …”

“…101 The convex side of the scoliotic curve is often contralateral to the lesional side of the spinal column. 66 The curvature is thought to arise as a reaction to pain.…”

“…42,65,83 Most patients tend to have an improvement or complete resolution of their deformity after the appropriate surgical intervention. 101 A delay in treatment may result in a progressive structural curve.…”

“…87 From a pathological perspective, the main differences between aggressive and conventional osteoblastomas lie within the ability of the aggressive variant to invade cortical bone, as well as the larger epithelioid osteoblasts relative to the conventional counterpart. 101 Aggressive osteoblastomas tend to be more immature and to show increased synthesis of alkaline phosphatase. 37 Other histopathological features of aggressive osteoblastomas include prominence of nucleoli, larger and more irregular trabeculae, eosinophilic cytoplasm, and a tendency to exhibit osteoclast-like cells more frequently.…”

“…Mild cellular pleomorphism as well as mitoses are occasionally seen in the more aggressive variant. 101 Preoperative alkaline phosphatase may be a screening tool to aid in differentiating aggressive from conventional osteoblastomas. Irrespective of the pathological aggressiveness, large osteoblastomas situated in precarious locations such as the craniovertebral junction and those that extend into the spinal canal often are the most worrisome to encounter for both patients and neurosurgeons.…”