Surgical management of spinal osteoblastomas

The Role of En Bloc Resection in the Modern Era for Primary Spine Tumors

STUDY DESIGN

A literature review.

OBJECTIVE

The aim of this review is to provide an overview of benign and malignant primary spine tumors and a balanced analysis of the benefits and limitations of (and alternatives to) surgical treatment with en bloc resection.

SUMMARY OF BACKGROUND DATA

Primary spine tumors are rare but have the potential to cause severe morbidity, either from the disease itself or as a result of treatment. The prognosis, goals, and treatment options vary significantly with the specific disease entity. Appropriate initial management is critical; inappropriate surgery before definitive treatment can lead to recurrence and may render the patient incurable, as salvage options are often inferior.

METHODS

We performed a comprehensive search of the PubMed database for articles relevant to primary spine neoplasms and en bloc spine surgery. Institutional review board approval was not needed.

RESULTS

Although Enneking-appropriate en bloc surgery can be highly morbid, it often provides the greatest chance for local control and/or patient survival. However, there is growing data to support modern radiotherapy as a feasible and less morbid approach to certain primary neoplasms that historically were considered radioresistant.

CONCLUSIONS

Choosing the optimal approach to primary spine tumors is complex. A comprehensive and up-to-date assessment of the evidence is required to guide patient care and to balance the often-competing goals of prolonging life and preserving quality of life.

Spinal tumours: recommendations of the Polish Society of Spine Surgery, the Polish Society of Oncology, the Polish Society of Neurosurgeons, the Polish Society of Oncologic Surgery, the Polish Society of Oncologic Radiotherapy, and the Polish Society of Orthopaedics and Traumatology

PURPOSE

The purpose of these recommendations is to spread the available evidence for evaluating and managing spinal tumours among clinicians who encounter such entities.

METHODS

The recommendations were developed by members of the Development Recommendations Group representing seven stakeholder scientific societies and organizations of specialists involved in various forms of care for patients with spinal tumours in Poland. The recommendations are based on data yielded from systematic reviews of the literature identified through electronic database searches. The strength of the recommendations was graded according to the North American Spine Society's grades of recommendation for summaries or reviews of studies.

RESULTS

The recommendation group developed 89 level A-C recommendations and a supplementary list of institutions able to manage primary malignant spinal tumours, namely, spinal sarcomas, at the expert level. This list, further called an appendix, helps clinicians who encounter spinal tumours refer patients with suspected spinal sarcoma or chordoma for pathological diagnosis, surgery and radiosurgery. The list constitutes a basis of the network of expertise for the management of primary malignant spinal tumours and should be understood as a communication network of specialists involved in the care of primary spinal malignancies.

CONCLUSION

The developed recommendations together with the national network of expertise should optimize the management of patients with spinal tumours, especially rare malignancies, and optimize their referral and allocation within the Polish national health service system.

Multimodal Imaging Evaluation and Clinical Progress of Spinal Osteoblastoma: A Comprehensive Review

Spinal osteoblastoma is rare clinically, with insidious onset, atypical symptoms, and various imaging manifestations, which can easily lead to misdiagnosis and delayed diagnosis. It can cause severe neurological dysfunction in patients with intermediate to advanced stages and may easily recur after surgery. Imaging examinations such as radiography, computed tomography, magnetic resonance imaging, and positron emission tomography have different value for the diagnosis of spinal osteoblastoma, but they lack specificity. The preferred treatment is surgical resection, which is technically difficult, and in some cases, osteoblastoma cannot be completely removed. New clinical approaches such as radiofrequency ablation, radiotherapy, targeted chemotherapy, and other comprehensive treatments have emerged and are progressing rapidly, but no unified norms have yet been developed. This manuscript provides a systematic review of the literature and provides an extensive and comprehensive review of this rare tumor in terms of multimodality imaging manifestations and clinical progress.

Benign Brain and Spinal Tumors Originating from Bone or Cartilage

Benign osseocartilaginous tumors of the spine are overall uncommon, representing between 1 and 13% of all primary bone tumors and less than 10% of all spinal tumors. Tumors in this category include osteoblastic lesions such as the related osteoid osteoma and osteoblastoma, and cartilage-forming lesions including osteochondroma, chondroma, and chondroblastoma. Aneurysmal bone cysts, giant cell tumors of bone, and eosinophilic granulomas also comprise benign tumors of the spine arising from bone. There is significant heterogeneity in the epidemiology, molecular biology, imaging features, and optimal treatment of these lesions. For example, osteoid osteoma is characterized by high expression of the cyclooxygenase enzymes, making it amenable to treatment with anti-inflammatory drugs initially, whereas other lesions such as osteoblastoma may require intralesional curettage or en bloc resection sooner. Generally, en bloc resection is preferred when possible to minimize risk of recurrence. Further, some tumors may arise in the setting of syndromic conditions, such as multiple chondromas arising in Ollier disease or Maffucci syndrome, or as part of genetic disorders, such as osteochondromas in the context of hereditary multiple exostosis. These lesions may present with local pain, cause neurological compromise or be discovered incidentally on routine imaging. The Enneking classification and Weinstein-Boriani-Biagini system are routinely used to classify lesions and assist in surgical planning. More novel techniques such as radiofrequency ablation and laser photocoagulation have been applied for the treatment of osteoid osteoma and may have utility in the treatment of other lesion types. A multidisciplinary approach is critical in the management of benign lesions of the spine, and both chemotherapeutic and surgical approaches are routinely used.

Intralesional Marginal Resection for Osteoblastoma in the Mobile Spine: Experience From a Single Center

Osteoblastoma (OB) is a benign bone tumor with aggressive behavior and a tendency for local recurrence. The appropriate surgical strategy for spinal OB remains unclear. This retrospective study aimed to verify the clinical efficacy and safety of intralesional marginal resection of OB in the mobile spine. We enrolled 50 consecutive patients with spinal OB between January 2009 and December 2019. The tumors were staged based on the Enneking system, with 21 and 29 lesions being determined as stage 2 (St.2) and stage 3 (St.3), respectively. Among them, 42 patients underwent intralesional marginal resection, five underwent extensive curettage, and three underwent en bloc resection successfully since their lesions were limited to the posterior element in a single vertebra. We analyzed clinical characteristics, perioperative and follow-up images, surgical details, and follow-up data. Within a median follow-up duration of 50 (range: 24–160) months, six (12.0%) patients had local recurrence. The recurrence rates among patients who underwent intralesional marginal resection, curettage, en bloc resection were 7.1%(3/42), 60.0%(3/5), and 0%(0/3), respectively. The recurrence rate of intralesional marginal resection of St.3 lesions was slightly higher than that of St.2 lesions (7.7%[2/26] vs. 6.3%[1/16]). There were 16(38.1%), 3(60.0%), and 0 patients with surgical complications among those who underwent intralesional marginal resection, curettage, and en bloc resection, respectively. Local recurrence was observed in five (5/14, 35.7%) patients who had vertebral artery extension and in none who did not have vertebral artery extension (p = 0.02). Our findings suggest that intralesional marginal resection could be an appropriate treatment choice for patients with spinal OB, both St.2 and St.3 lesions, with an acceptable local recurrence rate and a low risk of complications. Vertebral artery extension could be a strong risk factor for local recurrence in patients with spinal OB.

Primary Benign Tumors of the Spinal Canal

Benign tumors that grow in the spinal canal are heterogeneous neoplasms with low incidence; from these, meningiomas and nerve sheath tumors (neurofibromas and schwannomas) account for 60%-70% of all primary spinal tumors. Benign spinal canal tumors provoke nonspecific clinical manifestations, mostly related to the affected level of the spinal cord. These tumors present a challenge for the patient and healthcare professionals, for they are often difficult to diagnose and the high frequency of posttreatment complications. In this review, we describe the epidemiology, risk factors, clinical features, diagnosis, histopathology, molecular biology, and treatment of extramedullary benign meningiomas, osteoid osteomas, osteoblastomas, aneurysmal bone cysts, osteochondromas, neurofibromas, giant cell tumors of the bone, eosinophilic granulomas, hemangiomas, lipomas, and schwannomas located in the spine, as well as possible future targets that could lead to an improvement in their management.

Tailored surgery on aggressive osteoblastoma involving the cervicothoracic junction: an oncological and spinal stability long-term follow-up

INTRODUCTION

Aggressive osteoblastoma (AO) represents a rare tumor with borderline features between benign osteoblastoma and osteosarcoma. Having a local aggressive behavior without metastasizing attitude, radical excision is a mainstay treatment. Conversely, spine fusion technique is still debated. We report a rare case of cervicothoracic junction (CTJ) AO and the tailored decision-making process to choose the best treatment.

CASE PRESENTATION

A 34-year-old man complaining of neck pain was admitted to our department. Cervicothoracic MRI revealed a well-circumscribed lesion involving C7 left lamina with cortical erosion and mild spinal canal invasion. Additionally, STIR sequences exhibited a bright signal spreading through the posterior third of the C7 and T1 vertebrae which on T1-weighted and T2-weighted sequences appeared isointense and hyperintense, respectively. Therefore, the patient underwent a C7 laminotomy. Histology revealed an aggressive variant of osteoblastoma. Therefore, tumor was classified as AO and surgical management was reconsidered. A combined anterior and posterior approach was recommended to reach oncological radicality and spinal stability. At 6-years follow-up, patient remained neurologically intact without signs of recurrence and/or of instability.

DISCUSSION

Due to its rarity and mimicking features, diagnosis of AO results challenging. Due to its aggressive behavior, radical surgery is the mainstay treatment. Conversely, the most suitable fusion technique is still debated. A proper surgical management should be focused on oncological radicality to guarantee the total tumoral removal avoiding progression or recurrences. Similarly, a proper evaluation of the long-term spinal balance should be assessed to avoid developing of spinal deformities or instrumentation failures.

Feasibility of achieving planned surgical margins in primary spine tumor: a PTRON study

OBJECTIVE

Oncological resection of primary spine tumors is associated with lower recurrence rates. However, even in the most experienced hands, the execution of a meticulously drafted plan sometimes fails. The objectives of this study were to determine how successful surgical teams are at achieving planned surgical margins and how successful surgeons are in intraoperatively assessing tumor margins. The secondary objective was to identify factors associated with successful execution of planned resection.

METHODS

The Primary Tumor Research and Outcomes Network (PTRON) is a multicenter international prospective registry for the management of primary tumors of the spine. Using this registry, the authors compared 1) the planned surgical margin and 2) the intraoperative assessment of the margin by the surgeon with the postoperative assessment of the margin by the pathologist. Univariate analysis was used to assess whether factors such as histology, size, location, previous radiotherapy, and revision surgery were associated with successful execution of the planned margins.

RESULTS

Three hundred patients were included. The surgical plan was successfully achieved in 224 (74.7%) patients. The surgeon correctly assessed the intraoperative margins, as reported in the final assessment by the pathologist, in 239 (79.7%) patients. On univariate analysis, no factor had a statistically significant influence on successful achievement of planned margins.

CONCLUSIONS

In high-volume cancer centers around the world, planned surgical margins can be achieved in approximately 75% of cases. The morbidity of the proposed intervention must be balanced with the expected success rate in order to optimize patient management and surgical decision-making.

Minimally Invasive Resection of a Pediatric Lumbar Osteoblastoma: Case Report

BACKGROUND

Osteoblastomas are locally aggressive bone tumors typically affecting the posterior elements of the vertebral column. The treatment of choice is total surgical resection, traditionally through an open laminectomy, often with facetectomy and fusion when the lesion is in the foramen.

OBJECTIVE

To seek an alternative to open surgery, allowing quick and full functional recovery, to meet the youth and athlete population's specific surgical goals. In this population especially, open surgery can be associated with significant impairment and morbidity.

METHODS

 We report a pediatric case of posterior L5 osteoblastoma completely removed using a facet-sparing and fusion-avoiding contralateral foraminal minimally invasive approach using a tubular retractor system. A 12-yr-old male competitive tennis player presented with progressive right L5 lumbosciatica. Computed tomography scan and magnetic resonance imaging revealed a lesion of the right L5 pedicle, facet, and vertebral body with significant foraminal soft-tissue extension. Being unfit for percutaneous radiofrequency ablation, the patient underwent a minimally invasive biopsy and resection using an 18-mm-wide METRx nonexpandable tubular retractor (Medtronic) through a contralateral approach, sparing the facet and avoiding fusion surgery.

RESULTS

Postoperative imaging showed residual tumor. The patient was reoperated in a similar fashion with complete tumor removal. His symptoms resolved completely postoperatively. He resumed tennis within 4 mo and remains symptom- and tumor-free at 12-mo follow-up.

CONCLUSION

Minimally invasive contralateral facet-sparing resection of a pediatric lumbar osteoblastoma is an alternative to standard technique and is associated with significant advantages for young athletes, such as quick and full functional recovery, along with avoidance of fusion when the facet joint is involved.

Recurrent lumbar-origin osteoblastoma treated with multiple surgery and carbon ion radiotherapy: a case report

BACKGROUND

Although osteoblastoma is an uncommon benign bone tumor, it sometimes behaves in a locally aggressive fashion. We herein report a case of recurrent lumbar spine osteoblastoma that was treated by repeated surgery and carbon ion radiotherapy.

CASE PRESENTATION

A 13-year-old Japanese girl presented with left side lumbar pain. Computed tomography and magnetic resonance imaging of the lumbar spine demonstrated a tumorous lesion in the left side pedicle of L4. Although gross total resection of the mass, including the nidus, was performed in the initial surgery, recurrence was observed repeatedly in the short term and the pathological diagnosis of all of the resected tumors was conventional osteoblastoma. We finally performed carbon ion radiotherapy after the patient's 3rd palliative operation, and achieved a good outcome. No further recurrence has been observed in 10 years of follow-up.

CONCLUSION

We performed carbon ion radiotherapy for a case of recurrent spinal osteoblastoma and achieved a good outcome without recurrence at 10 years after carbon ion radiotherapy treatment. To the best of our knowledge, this is the first case of osteoblastoma that was treated with carbon ion radiotherapy after multiple surgeries.

Imaging algorithm and multimodality evaluation of spinal osteoblastoma

Background

To analyze the features of CT, MRI and PET/CT and their diagnostic value for spinal osteoblastomas (OBs).

Methods

The radiological and clinical data of 21 patients with histopathologically-confirmed spinal OBs were analyzed retrospectively.

Results

Sixteen of the 21 cases were benign and 5 were aggressive OBs. Tumors were located in the lumbar (n = 11), cervical (n = 4), thoracic (n = 5), and sacral (n = 1) spinal regions. Nineteen cases were centered in the posterior elements of the spine, 13 of which extended into the vertebral body. Punctate or nodular calcifications were found in all cases on CT with a complete sclerotic rim (n = 12) or incomplete sclerotic rim (n = 8). The flare phenomenon (indicative of surrounding tissue inflammation) was found in 17/21 cases on CT, thin in 11 cases and thick in 6 cases, and in 19/19 cases on MRI, thin in 1 case and thick in 18 cases. On ¹⁸F-FDG PET/CT, all cases (8/8) were metabolically active with the SUVmax of 12.3–16.0; the flare sign was observed in 8 cases, including 7 cases of hypometabolism and 1 case of coexistence of hypermetabolism and hypometabolism. Based on CT, 3, 12, and 6 cases were classified as Enneking stage 1, 2 and 3, respectively. Of 19 cases with MRI, 1 and 18 cases were classified as Enneking stage 2 and 3, respectively.

Conclusions

Spinal OB has multiple unique characteristic radiological features. Although a larger sample size is needed, combining CT, MRI and PET may be beneficial to optimize preoperative diagnosis and care of patients with OBs.

Full endoscopic resection of a lumbar osteoblastoma: technical note

Osteoblastomas are a rare, benign primary bone tumor accounting for 1% of all primary bone tumors, with 40% occurring within the spine. Gross-total resection (GTR) is curative, although depending on location, this can require destabilization of the spine and necessitate instrumented fixation. Through the use of minimally invasive, muscle-sparing approaches, these lesions can be resected while maintaining structural integrity of the spine. The authors present a case report and technical note of a single patient describing the use of a purely endoscopic technique to resect a right L5 superior articulating process osteoblastoma in a 45-year-old woman. The patient underwent an image-guided endoscopic resection of her superior articulating facet osteoblastoma. Intraoperative CT demonstrated GTR. On postoperative examination, she remained neurologically intact with resolution of her pain. At follow-up, she remained pain free. Resection of lumbar osteoblastoma through a fully endoscopic approach was a safe and effective technique in this patient. This technique allowed for GTR without compromising spinal structural integrity, thus eliminating the need for instrumented fixation.

Factors Affecting Prognosis of Patients With Osteoblastoma of the Mobile Spine: A Long-Term Follow-up Study of 70 Patients in a Single Center

BACKGROUND

Osteoblastoma (OBL) in the mobile spine is a benign tumor with aggressive potential. There is not much published information on OBL of the mobile spine as a result of rarity of the disease. There are controversies over the aggressive subtype and prognostic factors of the condition.

OBJECTIVE

To explore the aggressive subtype and investigate prognostic factors of OBLs in the mobile spine.

METHODS

A retrospective analysis of spinal OBL was performed by survival analysis. Patients in 2 cohorts were analyzed based on the Enneking grade and pathological evaluation. Local recurrence-free survival (RFS) was estimated using the Kaplan-Meier method to identify potential prognostic factors. Factors with P ≤ .05 were subjected to multivariate analysis by Cox regression analysis. P ≤ .05 were considered statistically significant.

RESULTS

Included in this study were 70 patients with spinal OBL who were followed up by a mean of 67.1 mo (range 24-188). Local recurrence was detected in 9 cases after initial surgery, and death occurred in 2 cases. The result of statistical analysis suggested that Epithelioid OBL (EO) with Enneking stage 3 (St.3) and total spondylectomy were independent prognostic factors for RFS.

CONCLUSION

St.3 or EO lesions seem to be more aggressive than St.2 or conventional osteoblastomas, but St.3 and EO should be considered simultaneously in predicting the aggressiveness of the lesion and the risk of recurrence. Total spondylectomy performed either by en bloc or piecemeal could significantly reduce recurrence of OBLs in the mobile spine.

Diagnostic and Management Options of Osteoblastoma in the Spine

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/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.

Neoadjuvant denosumab for the treatment of a sacral osteoblastoma

PURPOSE

To present a case of aggressive sacral osteoblastoma (OB) treated with neoadjuvant denosumab therapy and en bloc resection.

METHODS

Case report of a 14-year-old male with an aggressive OB affecting the superior articular process of the left first sacral segment. The lesion was lytic and metabolically active and involved the left-sided posterior elements of S1-S3 with extension into the spinal canal, affecting the left S1, S2, S3, S4 and S5 nerve roots. He was treated for 1 month with neoadjuvant denosumab followed by en bloc resection.

RESULTS

Denosumab therapy caused regression of the tumour and converted the diffuse infiltrative mass into a well-defined solid (osteoma-like) structure, aiding surgical resection and preserving the S1, S4 and S5 nerve roots. Histologically, the treated lesion showed abundant sclerotic woven bone and osteoblasts with absence of osteoclasts.

CONCLUSIONS

A short course of denosumab caused tumour regression, ossification and conversion of an aggressive OB into a sclerotic, well-defined lesion thus aiding surgical resection and preservation of neural structures. Neoadjuvant therapy reduced osteoclast numbers but PET showed that the lesion remained FDG avid post-therapy.