Surgical Strategy for Spinal Dumbbell Tumors: A New Classification and Surgical Outcomes

A Novel and Reproducible Classification of Cervical Dumbbell Tumors to Inform Surgical Approach and Reconstruction Techniques

STUDY DESIGN

A retrospective case series.

OBJECTIVE

This study developed a novel classification system based on imaging and anatomy to select optimal surgical approaches and reconstruction strategies to achieve total resection of cervical dumbbell tumors and restore spinal stability.

SUMMARY OF BACKGROUND DATA

Total resection is necessary to decrease the recurrence rate of cervical dumbbell tumors. Previous cervical dumbbell tumor classifications are insufficient for determining surgical strategies; therefore, a practical classification is needed.

MATERIALS AND METHODS

This study included 295 consecutive patients with cervical dumbbell tumors who underwent total surgical resection. A novel classification of cervical dumbbell tumors was developed based on magnetic resonance imaging and computed tomography. Continuous variables were expressed as mean±SD and were compared using an unpaired two-tailed Student t test. The χ 2 test or the Fisher exact test was used for categorical variables. Kendall's W test assessed three independent raters' inter-rater and intrarater reliabilities on 140 cervical dumbbell tumors.

RESULTS

The inter-rater and intrarater consistency coefficient was 0.969 (χ 2 =404.3, P <0.001) and 0.984 (χ 2 =273.7, P <0.001). All patients with type I and II tumors underwent single-posterior surgeries to achieve total resection. Of the patients in this study, 86.1%, 25.9%, 75.9%, and 76.9% underwent posterior surgeries for types IIIa, IIIb, IVa, and V tumors, respectively. All patients with type IVb tumors underwent a combined anterior and posterior approach. Posterior internal fixation was used for all patients in posterior surgery. Anterior reconstruction was applied for patients with type IVb tumors (20/20, 100%) and some with type V tumors (3/13, 23.1%). The mean follow-up duration was 93.6±2.6 months. A recurrence was observed in 19 (6.4%) patients.

CONCLUSION

The authors describe a novel classification system that is of practical use for planning the complete resection of cervical dumbbell tumors.

Giant "Dumbbell" Thoracic Schwannoma: Radical Excision of Rare Lesion in One Surgical Time by Combined Neurosurgical and Thoracoscopic Approach

Dumbbell-shaped schwannomas are slow-growing tumors that are typically benign lesions. They account for 6%-14% of spinal neoplasms, with 30% having intradural and extradural components.1 A schwannoma is considered "giant" if it extends beyond the spine by >2.5 cm and involves more than 2 vertebral levels.2 The Eden classification categorizes these tumors into 4 types on the basis of the primary component.3 Surgery is recommended for individuals experiencing prolonged nerve damage and persistent neurogenic pain that cannot be managed.2 There are 3 surgical options for managing thoracic dumbbell schwannomas4: the single-stage posterior-only approach,5 the single-stage anterior-only approach,6 and the single-stage combined posteroanterior neurosurgical and video-assisted thoracoscopic approach. The latter option allows for the most comprehensive lesion control including vascular and nerve structures and optimal hemostasis control. It also avoids spinal instrumentation and provides certainty for complete tumor removal.7Video 1 shows a surgical procedure performed on a 58-year-old woman to remove a thoracic dumbbell neurinoma. The patient consented to the procedure and publication of her image. A simultaneous thoracoscopic and neurosurgical approach was performed. The surgical team successfully removed the schwannoma, and the patient's recovery was smooth, with no neurologic issues or pain. This case highlights the benefits of using a single-stage combined approach for treating Eden II and Eden III giant dumbbell thoracic schwannomas.

Comparison of the surgical outcomes of the posterior approach, video-assisted thoracic surgery, and combined approach for thoracic dumbbell tumors based on a new classification: a retrospective study

The appropriate surgical treatment strategy was based on the regions of tumor invasion. There is no classification to aid the surgeon in selection. A retrospective study of the clinical data of patients who underwent resection of thoracic dumbbell tumors at the Neurosurgery and Thoracic Surgery Department of Hospital between January 1, 2016, and December 31, 2021 was conducted. Patient data, images, and surgical outcome data were collected. The thoracic spine was divided into areas A, B, and C with respect to the line through the middle of the intervertebral foramen and the line of the costo-transverse joint lateral margin in the horizontal plane. Type I tumors were located in areas A or A and B, type II tumors were located in areas B or B and C, and type III tumors were located in areas A, B, and C. Fifty-five patients with thoracic dumbbell tumors were surgically treated (mean age, 43.1 years; 22 (40%) female). The patients with type I and III tumors underwent the posterior approach, type III tumors had more bleeding during the operation and longer operation times than type I. Among the patients with type II tumors who underwent video-assisted thoracic surgery and the posterior approach, the posterior group had more bleeding and a longer operation time than the others. The patients with type III tumors underwent the combined approach and the posterior approach; although there was no clear difference in the bleeding volume or operation time, the combined approach group had a lower incidence of complications. The new classification of different types of thoracic dumbbell tumors can simply and effectively guide the selection of surgery.

Impact of Surgical Resection Without Spinal Fusion for Thoracic Dumbbell Tumors on Postoperative Global Spinal Sagittal Alignment and Clinical Outcomes

STUDY DESIGN

A retrospective comparative study.

OBJECTIVES

This study investigated radiographical changes in global spinal sagittal alignment (GSSA) and clinical outcomes after tumor resection without spinal fusion in patients with thoracic dumbbell tumors.

METHODS

Thirty patients with thoracic dumbbell tumors who were followed up for at least 3 years were included in this study. Variations in the outcome variables were analyzed using individual GSSA parameters measured on radiography. Clinical outcomes were assessed using the modified McCormick scale (MMCS), Japan Orthopaedic Association (JOA) score, and visual analog scale (VAS). To assess the impact of the affected levels on these outcomes, we divided the patients into three groups according to the location of the tumor (upper [T1-4], middle [T5-8], or lower [T9-12] thoracic spine).

RESULTS

The GSSA parameters (cervical lordosis, T1 slope, thoracic kyphosis [global, upper, middle, and lower], thoracolumbar kyphosis, lumbar lordosis, sacral slope, pelvic incidence, and pelvic tilt) of all the patients did not change significantly after surgery. Eleven of thirty patients had preoperative gait disturbances but they could walk without support (MMCS grade I or II) at the final follow-up. The JOA score and VAS showed significant postoperative improvements. No statistically significant differences were observed in each postoperative sagittal profile or clinical outcome between the upper, middle, and lower groups.

CONCLUSIONS

Tumor resection without spinal fusion did not affect the various GSSA parameters and resulted in satisfactory clinical outcomes, indicating that spinal fusion may not always be necessary when resecting thoracic dumbbell tumors.

Spinous Process-Splitting Laminectomy Approach for Tumor Excision at Conus Medullaris or Cauda Equina Level Results in Satisfactory Clinical Outcomes Without Affecting Global Spinal Sagittal Alignment

STUDY DESIGN

Retrospective comparative study.

OBJECTIVES

The present study investigated radiographical changes in global spinal sagittal alignment (GSSA) and clinical outcomes following tumor resection using spinous process-splitting laminectomy (SPSL) approach without fixation in patients with conus medullaris (CM) or cauda equina (CE) tumor.

METHODS

Forty-one patients with CM or CE tumor (19 males, 22 females, mean age at surgery of 52.9 ± 13.0 years) were included in this study. The variations of outcome variables were analyzed in various GSSA profiles using radiographic outcomes. The clinical outcomes were assessed using Japan Orthopaedic Association (JOA) score and JOA back pain evaluation questionnaire (JOABPEQ).

RESULTS

In all cases, the various GSSA parameters (sagittal vertical axis, C2-7 lordosis, T1 slope, thoracic kyphosis, T10-L2 kyphosis, lumbar lordosis [LL; upper, middle, and lower], sacral slope, pelvic incidence, and pelvic tilt) did not significantly change in the 2-years postoperative period. Moreover, age at surgery, the number of resected laminae, preoperative T12-L2 kyphosis, or LL did not affect the postoperative changes in T12-L2 kyphosis or LL, and had no statistically significant correlation among them. The scores of each postoperative JOA domain and the Visual Analogue Scale included in the JOABPEQ were significantly improved. There was no statistical significant group difference in each sagittal profile or clinical outcomes between CM and CE groups postoperatively.

CONCLUSIONS

Tumor resection using SPSL approach did not affected the various GSSA parameters examined and resulted in satisfactory clinical outcomes, indicating that SPSL approach is a suitable surgical technique for patients with CM or CE tumor.

Resection of Cervical Dumbbell-Shaped Schwannoma Using Posterior Unilateral Approach: Impact on Postoperative Cervical Function and Clinical Outcomes

STUDY DESIGN

A retrospective comparative study.

OBJECTIVES

This study aimed to evaluate the radiographical changes in cervical sagittal alignment (CSA) and clinical outcomes after tumor resection using a posterior unilateral approach without spinal fixation for patients with cervical dumbbell-shaped schwannoma (DS).

METHODS

Seventy-three patients with DS who were followed up for at least 2 years were included. The Eden classification was used to designate the types of DS. The CSA and range of motion (ROM) were analyzed using radiographs. The clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) score and JOA cervical myelopathy questionnaire.

RESULTS

The CSA in the neutral, flexion, and extension position and cervical ROM were not significantly reduced in the follow-up period. The JOA scores showed significant improvement after surgery. The postoperative radiographic parameters and clinical outcomes of Eden type II or III DS, which needed facetectomy for the resection, did not show any statistically significant difference compared with those of Eden type I tumor, which was resected without facetectomy. Fifty-two cases (71.2%) achieved gross total resection, whereas 21 cases (28.8%) remained in partial resection (PR). One case underwent reoperation due to the regrowth of the remnant tumor whose margin was at the entrance of the intervertebral foramen.

CONCLUSIONS

Tumor resection using the posterior unilateral approach preserved CSA and resulted in favorable clinical outcomes in patients with DS. When the resection ends in PR, the proximal margin of the remnant tumor should be located distally away from the entrance of the foramen to prevent regrowth.

Mid- to Long-Term Outcomes After Resection of Thoracic Dumbbell Tumors Managed by Laminectomy and Unilateral Total Facetectomy Without Instrumented Fusion

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVE

To evaluate mid- to long-term surgical outcomes of thoracic dumbbell tumors managed by laminectomy and unilateral total facetectomy without instrumented fusion.

METHODS

A total of 15 patients with thoracic dumbbell tumors who underwent primary resection by laminectomy and unilateral total facetectomy without spinal instrumented fusion between 2000 and 2015 were reviewed. Patient characteristics, surgical outcomes (including spinal alignment and stability), disc degeneration, pain, disability, and health-related quality of life were evaluated. Additionally, to analyze the impact of the affected levels on these outcomes, we divided the patients into 2 groups: a middle thoracic group and a thoracolumbar group.

RESULTS

The mean duration of follow-up was 100.5 months (range, 36-190 months). The affected level was T3-T4 or below in all patients. Although the local kyphosis angle (8.1° to 12.7°), thoracic kyphosis angle (25.6° to 33.9°), and coronal Cobb angle (6.6° to 9.5°) significantly increased from preoperative to the final visit (P ≤ .02), no patient demonstrated spinal instability. From magnetic resonance imaging, no patient had a worse grade of disc degeneration in the affected level than those in the adjacent levels. The percentage of patients who presented with an Oswestry disability index ≤ 22% was 80%. Moreover, the surgical region did not adversely affect the outcomes. No patient required additional surgery due to spinal instability or deformity.

CONCLUSIONS

Unilateral total facetectomy without fusion to resect thoracic dumbbell tumors caused neither spinal deformity nor instability requiring additional surgery at the mid- to long-term follow-up.

Diagnostic value of MRI in coexistence of schwannoma and meningioma mimicking a single dumbbell-shaped tumor in high cervical level. Case series and literature review

CONTEXT

Concurrent schwannoma and meningioma arising in the high cervical level mimicking a single dumbbell-shaped tumor is significantly rare, most of them were found during the surgeries or postoperative histological findings unexpectedly. The specific feature of schwannoma and meningioma coexistence in high cervical level on MR images has not been clearly described yet.

FINDINGS

We presented four cases of concurrent extradural schwannoma and intradural meningioma mimicking a single dumbbell-shaped tumor arising in the high cervical level. There was no interconnection between intradural and extradural masses in any case. In MRI reviews, the signal intensity between intradural lesions and spinal cord was similar on T2 weighted MR images. However, on contrast-enhanced MR images, the intradural lesions were more enhanced than spinal cord and presented as crescent-shaped intradural minor lesions adjacent to the more significantly enhanced extradural major tumor. These MRI findings could not be easily identified without meticulous observation preoperatively. Postoperative pathological findings confirmed the discrete tumors arising in the same cervical level.

CONCLUSION

The comparison of signal intensity changes among the spinal cord, intradural tumor and extradural tumor between T2 weighted and contrast-enhanced MR images may be helpful to predict coexistent schwannoma and meningioma in the high cervical level preoperatively. Intradural exploration is highly recommended when less enhanced crescent-shaped intradural minor lesion was observed adjacent to the significantly enhanced dumbbell-shaped major tumor in preoperative MRI findings.

Malignant Transformation and Metastatic Spread of Dumbbell-Shaped Meningeal Melanocytoma of the Cervical Spine: A Case Report and Literature Review

Background

Meningeal melanocytoma is a rare disease that originates from leptomeningeal melanocytes in the central nervous system. Meningeal melanocytoma is generally considered benign, and has a good prognosis following complete surgical resection. Reports of the malignant transformation and spread of these tumors are scarce.

Case Presentation

A 19 year old female presented with headache, progressive limb weakness, and dyspnea. Magnetic resonance imaging showed a dumbbell-shaped lesion at C1–C2 that was hyperintense on T1 weighted images and showed strong contrast enhancement. Total resection was achieved using a posterior midline approach. Post-operative pathology showed meningeal melanocytoma. The tumor recurred 9 months later with intracranial spread. Resection of the lesion revealed malignant transformation to meningeal melanoma.

Conclusion

Meningeal melanocytoma harbors malignant potential even with total resection. Radiotherapy could be considered to prevent disease recurrence and progression.

Minimally Invasive Posterolateral Approach for Surgical Resection of Dumbbell Tumors of the Lumbar Spine

Minimally invasive spine surgery (MISS) has many advantages over traditional open surgical procedures that can be conducted for the therapy of different diseases of the spine. MISS provide many prospective advantages such as, for example, small incisions, less damage to soft tissues, early activation of patients, and a shorter postoperative hospital stay. The aim of the study was to evaluate institutional experience with Dumbbell tumors and metastatic lesions of the lumbar spine and compare it with traditional open surgical resection of this type of tumors. Fourteen patients underwent the surgery with minimally invasive posterolateral approach in experimental group, and 10 patients of the control group were operated using the traditional open surgery procedure at the Department of spinal neurosurgery and pathology of peripheral nervous system of JSC “National Center for Neurosurgery.” The intraoperative neuro monitoring system (ISIS IOM System Compact, Inomed, Germany) was used in both groups. Sensory and motor evoked potentials were intraoperatively recorded. The present study was approved by the local Ethics Committee of the National Center for Neurosurgery. Patients signed informed consent before the surgical procedure. The experimental group included 14 patients, that underwent the surgery during the period from January 2020 till March 2021. And the control group included 10 patients that was operated from January 2018 to December 2019. The results of the treatment in both groups were assessed according to the generally accepted visual analog scale (VAS) and the Oswestry scales before, on the third day, and 3 months after the surgery. In experimental group, average reduction of the pain syndrome of 3.36 points (from 3 to 0 points) was observed in patients postoperatively according to the VAS 3 days, and of 4.0 points (from 2 to 0 points) 3 months after surgical procedures. Improvement by 23.86% (36–16%) was also observed using the Oswestry Disease Index (ODI) 3 days after the surgery, and then reduced to 21.00% (16–34%) in average in 3 months. All patients were revived 3 h after transfer to the specialist department. The average stay in the hospital was 6.5 (9–4) days in both groups. In control group, average reduction of the pain syndrome of 2.60 points (from 4 to 1 points) was observed postoperatively according to the VAS 3 days after the operation, and of 3.9 points (from 2 to 0 points) 3 months after the surgery. The ODI of patients was also improved by an average of 35.40% (50–20%) 3 days after the surgical procedure, and reduced to 24.20% (16–32%) in average 3 months after the surgery.

Chondromas of the Lumbar Spine: A Systematic Review

STUDY DESIGN

Systematic review and illustrative case.

OBJECTIVES

Lumbar spinal chondromas (LSCs) are rare spine tumors. The characteristics of these intraspinal lesions are not well described in the literature. The goal of this article is to describe the features of this rare spinal tumor.

METHODS

A PubMed and Scopus search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed to include studies reporting patients with LSCs. The data gathered from this review was analyzed to characterize LSCs.

RESULTS

The search yielded 14 cases of patients with LSCs. All studies were case reports (Level V of evidence). Different characteristics of LSCs are described, including demographics, clinical findings, imaging, and treatment.

CONCLUSIONS

The results of this review show that LSCs are almost exclusively seen in the extradural space and may adopt a dumbbell shape. LSCs frequently manifest in a very similar way to lumbar disc herniations; therefore, they should be considered in the differential diagnosis of sciatica, especially if magnetic resonance imaging with gadolinium shows peripheral rim enhancement of the lesion. Different degrees of improvement are usually observed after surgical treatment of these patients.

Lumbar Extraosseous Intraforaminal Osteoblastoma: Case Report and Review of the Literature

BACKGROUND

Osteoblastomas are rare primary bone tumors with a predilection for the spine. The extraosseous growth pattern is rare, and to our knowledge, only 2 cases of fully extraosseous osteoblastomas have been previously reported.

CASE DESCRIPTION

A man aged 36 years presented with a 7-month history of low back pain radiating to the gluteal area. On examination, a typical L5 radiculopathy was noted. The radiologic examinations conducted in the previous months pointed out the rapid growth of an extraosseous mass occluding the right L5-S1 foramen. Partial laminectomy was performed to achieve gross total resection. Histological analysis was consistent with osteoblastoma.

CONCLUSIONS

Osteoblastomas with extraosseous extension are uncommon, and an exclusively extraosseous presentation is anecdotal. This can lead to preoperative misdiagnosis when typical radiologic characteristics of bone-forming tumors are missing. We describe the case of an extraosseous lumbar osteoblastoma whose clinical and radiologic presentation was suggestive of malignancy.

Subtotal resection of cervical schwannomas and growth rate of residual tumors

OBJECTIVE

The objective of this study was to elucidate the features and surgical outcomes of cervical schwannomas.

METHODS

The authors retrospectively reviewed the records of 90 patients who underwent surgically treated cervical schwannomas from January 1995 to December 2017, with an emphasis on MRI findings such as tumor location, tumor size, extent of tumor resection, and growth of a residual tumor.

RESULTS

This study included 51 men (56.7%) and 39 women (43.3%) with a mean age of 44.5 years (range 7-77 years). Dumbbell-shaped tumors comprised 62 (68.9%) of 90 cases and gross-total resection (GTR) was achieved in 59 (65.6%) of 90 cases. All nondumbbell tumors (n = 28) underwent GTR. Only 1 case of recurrence in the GTR group showed a gradual increase in size (by 8.9 mm) during the 150-month follow-up period. For the regrowth patients in the subtotal resection group, the mean percentage increase in tumor size was 47.5% ± 33.1% and the mean growth rate was 5.8 ± 4.6 mm/year during the 20.3-month follow-up period. However, the size of residual tumor spontaneously decreased by a mean of 8.3% ± 11.1% during the 48.4-month follow-up period in the nonregrowth group.

CONCLUSIONS

These findings suggested that frequent MRI follow-up examinations are required for residual schwannomas in the cervical spine for at least 2 years, and continuous MRI follow-ups are also required thereafter.

SPINAL DUMBBELL EPIDURAL HEMANGIOMA: TWO STAGE/SAME SITTING/SAME POSITION POSTERIOR MICROSURGICAL AND TRANSTHORACIC ENDOSCOPIC RESECTION - CASE REPORT AND REVIEW OF THE LITERATURE

- Spinal dumbbell tumors are defined by a narrowing at the point where they penetrate the intervertebral foramina or dura mater, assuming an hourglass or dumbbell shape. Dumbbell-shaped spinal hemangiomas are extremely rare. We describe a dumbbell spinal tumor (epidural cavernous hemangioma) resected by a 2-stage single-sitting combined approach. We also conduct a substantial literature review of the subject. We present a case of a 78-year-old male who was found to have a homogeneously enhancing, dumbbell-shaped, intraspinal, extradural tumor mass extending into the left chest cavity. The tumor was resected with a single-sitting 2-stage posterior technique: a microsurgical approach, followed by endoscopic resection via a thoracoscopic approach. There are several reports in the literature on the combined approach for dumbbell tumors of the spinal cord. Our case is the first to describe 2-stage combined surgery in 1 sitting for dumbbell hemangioma with the patient in the lateral decubitus position for the thoracoscopic part of the surgery; and the use of a fat pad, which was applied in the neuroforamen via the posterior route, as a marker for resection during the transthoracic procedure.

Minimally invasive resection of large dumbbell tumors of the lumbar spine: Advantages and pitfalls

OBJECTIVES

The surgical management of dumbbell tumors of the lumbar spine remains controversial, because of their large volume and complex location, involving both the spinal canal and the retro peritoneum. While sporadically reported, our study aims to confirm the value of minimally invasive posterior access for the complete resection of large lumbar dumbbell tumors.

PATIENTS AND METHODS

In this prospective study, we included all consecutive patients who underwent the resection of a voluminous dumbbell tumor at the lumbar spine through a minimally invasive approach, between March 2015 and August 2017. There were 4 men and 4 women, with a mean age at diagnosis of 40.6 years (range 29-58 years). The resection was performed through a trans muscular tubular retractor by the same surgical team. Operative parameters and initial postoperative course were systematically reported. Clinical and radiological monitoring was scheduled at 3 months, 1 year and 2 years.

RESULTS

The mean operative time was 144 min (range 58-300 minutes) and the mean estimated blood loss was 250 ml (range 100-500 ml). Gross total resection was achieved in all patients. No major complication was reported. The mean length of hospital stay was 3.1 days (range 2 to 6 days). Histological analysis confirmed the diagnosis of grade 1 schwannoma in all patients. The mean follow up period was 14.9 months (range 6 to 26 months), and 5 patients completed at least 1-year follow-up. At 6 months the Macnab was excellent in 6 patients, good in one patient and fair in one patient because of residual neuropathic pain requiring the maintenance of a long-term treatment. No tumor recurrence was noted to date.

CONCLUSION

Lumbar dumbbell tumors can be safely and completely resected using a single-stage minimally invasive procedure, in a trained team.