Neuroimaging of Spinal Tumors

Intradural Extramedullary Tumors and Associated Syndromes

Most intradural tumors are located within the intradural extramedullary compartment, and the most common tumors are schwannomas and meningiomas. Other less common neoplasms include neurofibroma, solitary fibrous tumor, myxopapillary ependymoma, lymphoma, metastatic leptomeningeal disease, malignant peripheral nerve sheath tumor, and paraganglioma. Patients usually present with gait ataxia, radicular pain, and motor and sensory deficits due to chronic compressive myelopathy or radiculopathy. MRI is the modality of choice for detecting and evaluating intradural extramedullary spinal tumors. This imaging technique helps narrow the differential diagnosis and therefore decide treatment.

Conventional and Advanced Imaging of Spinal Cord Tumors

Spinal cord tumors are best identified by conventional MR imaging with contrast. Most intramedullary spinal cord tumors have characteristic MR imaging features that allow an accurate preoperative diagnosis. The spinal cord tumors reviewed in this article include the most common tumors, ependymomas and astrocytomas, as well as the less common tumors such as hemangioblastomas and metastases. Rare tumors such as primary CNS lymphoma and melanocytic tumors are also described. Advanced imaging techqniques of more common intramedullary tumors are also reviewed.

Benign Spinal Tumors

Benign spinal intradural tumors are relatively rare and include intramedullary tumors with a favorable histology such as low-grade astrocytomas and ependymomas, as well as intradural extramedullary tumors such as meningiomas and schwannomas. The effect on the neural tissue is usually a combination of mass effect and neuronal involvement in cases of infiltrative tumors. The new understanding of molecular profiling of different tumors allowed us to better define central nervous system tumors and tailor treatment accordingly. The mainstay of management of many intradural spinal tumors is maximal safe surgical resection. This goal is more achievable with intradural extramedullary tumors; yet, with a meticulous surgical approach, many of the intramedullary tumors are amenable for safe gross-total or near-total resection. The nature of these tumors is benign; hence, a different way to measure outcome success is pursued and usually depends on functional rather than oncological or survival outcomes.

Intradural extramedullary cavernous hemangioma of the cervicothoracic junction: A case report and review of the literature

Background:

Intradural extramedullary cavernous hemangiomas of the spine are rare, benign lesions with only 40 published cases to date.

Case Description:

The authors report a rare case of a histologically diagnosed intradural extramedullary cavernous hemangioma of the spine involving the cervicothoracic junction and causing sudden gait disturbances and urinary retention in a 24-year-old male. Gross total tumor removal allowed complete spinal decompression and sensible improvement of the clinical condition with no evidence of tumor relapse at 12-month follow-up examination.

Conclusion:

More frequently found in the lower thoracic and lumbar spine, these tumors often cause subtle clinical manifestations including sensory and motor dysfunction secondary to nerve root compression; nonetheless, occasional cases of rapidly progressive worsening of the neurological condition with evidence of myelopathy and autonomic dysfunction have been described. In such cases, urgent surgical resection is crucial since the degree of neurological impairment and the time spanned from the onset of the symptoms are paramount for a good recovery.

Agreement and differentiation of intradural spinal cord lesions in dogs using magnetic resonance imaging

Background

Magnetic resonance imaging is the method of choice for diagnosing spinal cord neoplasia, but the accuracy of designating the relationship of a neoplasm to the meninges and agreement among observers is unknown.

Objectives

To determine agreement among observers and accuracy of diagnosis compared with histology when diagnosing lesion location based on relationship to the meninges.

Animals

Magnetic resonance images from 53 dogs with intradural extramedullary and intramedullary spinal neoplasms and 17 dogs with degenerative myelopathy.

Methods

Six observers were supplied with 2 sets of 35 images at different time points and asked to designate lesion location. Agreement in each set was analyzed using kappa (κ) statistics. We tabulated total correct allocations and calculated sensitivity, specificity, and likelihood ratios for location designation from images compared with known histologic location for lesions confined to 1 location only.

Results

Agreement in the first set of images was moderate (κ = 0.51; 95% confidence interval [CI], 0.43‐0.58) and in the second, substantial (κ = 0.69; 95% CI, 0.66‐0.79). In the accuracy study, 180 (75%) of the 240 diagnostic calls were correct. Sensitivity and specificity were moderate to high for all compartments, except poor sensitivity was found for intradural extramedullary lesions. Positive likelihood ratios were high for intradural extramedullary lesions and degenerative myelopathy.

Conclusions and Clinical Importance

Overall accuracy in diagnosis was reasonable, and positive diagnostic calls for intradural extramedullary lesions and negative calls for intramedullary lesions are likely to be helpful. Observers exhibited considerable disagreement in designation of lesions relationship to the meninges.

S-100-negative, GNA11 mutation-positive intramedullary meningeal melanocytoma of the thoracic spine: A radiographic challenge and histologic anomaly

Background:

Intramedullary melanocytomas are exceedingly rare and their management is largely based on case reports and small clinical series. They have characteristic imaging and histologic findings that can aid in their diagnosis. Genetic testing may be required for definitive diagnosis and management guidance in ambiguous cases.

Case Description:

We present the case of a thoracic intramedullary meningeal melanocytoma in a patient unable to undergo an MRI.

Conclusion:

This is the first reported S-100-negative case with genetic testing to support the diagnosis of a rare intramedullary melanocytoma.

MRI characteristics and resectability in spinal cord glioma

OBJECTIVE

The histopathology of intramedullary spinal cord tumors (IMSCT) can be suspected from the MRI features and characteristics. Ultimately, the confirmation of diagnosis requires surgery. This retrospective study addresses MRI features including homogeneity of enhancement, margination, and associated syrinx in intramedullary astrocytomas (IMA) and ependymomas (IME) that assist in diagnosis and predict resectability of these tumors.

METHODS

Single-center retrospective analysis of IMA and IME cases since 2005 extracted from the departmental registry/electronic medical records post IRB approval (IRB 201,710,760). We compared imaging findings (enhancement, margination, homogeneity, and associated syrinxes) between tumor types and examined patient outcomes.

RESULTS

There were 18 IME and 21 IMA. On preoperative MRI, IME was favored to have homogenous enhancement (OR 1.8, p = 0.0001), well-marginated (p < 0.0001, OR 0.019 [95 % CI 0.002-0.184]), and associated syrinx (p = 0.015, OR 0.192 [95 % CI 0.049-0.760]). Total excision, subtotal excision, and biopsy were performed in 12, 5, and 1 patients in the IME cohort, respectively. In the IMA group, tumors were heterogeneous and poorly marginated in 20 of the 21 patients. Total excision, subtotal excision, and biopsy were undertaken in 2, 13, and 6 patients, respectively. The success of excision was predicted by MRI, with a significant difference in the extent of resection between IME and IMA (X2 = 14.123, p = 0.001). In terms of outcome, ordinal regression analysis showed that well-margined tumors and those with homogeneous enhancement were associated with a better postoperative McCormick score. Extent of resection had statistically significant survival (p = 0.026) and recurrence-free survival (p = 0.008) benefits.

CONCLUSION

The imaging characteristics of IME and IMA have meaningful clinical significance. Homogeneity, margination, and associated syrinxes in IME can predict resectability and complexity of surgery.

Evaluating the Clinical Utility and Cost of Imaging Strategies in Adults with Newly Diagnosed Primary Intradural Spinal Tumors

OBJECTIVE

In patients with new primary intradural spinal tumors, the best screening strategy for additional central nervous system (CNS) lesions is unclear. The goal of this study was to document the rate of additional CNS tumors in these patients.

METHODS

Adults with primary intradural spinal tumors were retrospectively reviewed. Imaging strategy at diagnosis was classified as focused spine (cervical, thoracic, or lumbar), total spine, or complete neuraxis (brain and total spine). Tumor pathology, genetic syndromes, and presence of additional CNS lesions at diagnosis or follow-up were collected.

RESULTS

The study comprised 319 patients with mean age of 51 years and mean follow-up of 41 months. In 151 patients with focused spine imaging, 3 (2.0%) were found to have new lesions with 2 (1.4%) requiring treatment. In 35 patients with total spine imaging, there were no additional lesions. In 133 patients with complete neuraxis imaging, 4 (3.0%) were found to have new lesions with 2 (1.5%) requiring treatment. There was no difference in the identification of new lesions (P = 0.542) or new lesions requiring treatment (P = 0.772) across imaging strategies. Among patients without genetic syndromes, rates of new lesions requiring treatment were 1.4% for focused spine, 0% for total spine, and 2.2% for complete neuraxis (P = 0.683). There were no cases of delayed identification causing risk to life or neurological function. Complete neuraxis imaging carried an increased charge of $4420 per patient.

CONCLUSIONS

Among patients without an underlying genetic syndrome, the likelihood of identifying additional CNS lesions requiring treatment is low. In appropriate cases, focused spine imaging may be a more cost-effective strategy.

Intramedullary tumours and tumour mimics

Spinal cord lesions are traditionally classified as either extradural or intradural extramedullary or of intramedullary origin. Intramedullary spinal cord tumours are histopathologically similar to cranial tumours with a diverse range of pathologies. Astrocytomas and ependymomas account for approximately 80% of all intramedullary tumours, with other primary and secondary lesions accounting for the remaining 20%. Magnetic resonance imaging is the preferred imaging modality for diagnosing and characterising spinal cord lesions; however, accurate characterisation of tumour histology can be challenging, and is further confounded by intramedullary non-neoplastic lesions, such as demyelinating vascular, inflammatory, infectious, or traumatic lesions. This review illustrates the spectrum of intramedullary tumours and tumour mimics with emphasis on the imaging findings.

Stereotactic Radiosurgery for Benign Spinal Tumors

Benign spinal tumors are rare clinical conditions, including meningiomas, schwannomas, and neurofibromas. Although these tumors are usually treated with open surgical resection, spinal stereotactic radiosurgery may be a safe and effective alternative to surgery in selected patients.

Nervous System Hemangiopericytoma

The management of patients harboring central nervous system (CNS) hemangiopericytomas (HPCs) is a partially answered challenge. These are rare locally aggressive lesions, with potential for local recurrence, distal neural metastasis (DNM), and extraneural metastasis (ENM). Resection, when feasible, remains the initial treatment option, providing histological diagnosis and immediate relief of tumor-related mass effect. Patients receiving surgery alone or surgery and external beam radiotherapy (EBRT) show improved overall survival (OS) and progression-free survival as compared to those undergoing a biopsy alone (p = 0.01 and p = 0.02, respectively). Yet, in many instances, patient and tumor-related parameters preclude complete resection. EBRT or stereotactic radiosurgery (SRS) shares a significant role in achieving local tumor control, not shown to impact OS in HPC patients. The benefits of SRS/EBRT are clearly limited to improved local tumor volume control and neurologic function, not affecting DNM or ENM development. SRS provides acceptable rates of local tumor volume control coupled with treatment safety and a patient-friendly apparatus and procedure. Single-session SRS is most effective for lesions measuring <2 cm in their largest diameter (10 cm3 volume), with prescription doses of at >15 Gy. Systemic HPC disease is managed with various chemotherapeutic, immunotherapeutic, and anti-angiographic agents, with limited success. We present a short discussion on CNS HPCs, focusing our discussion on available evidence regarding the role of microsurgical resection, EBRT, SRS, chemotherapy, and immunotherapy for upfront, part of adoptive hybrid surgery approach or for recurrent HPCs.

Current surgical strategies for treating spinal tumors: Results of a questionnaire survey among members of the German Spine Society (DWG)

PURPOSE

Questionnaire survey among the members of the German Spine Society (Deutsche Wirbelsäulen-Gesellschaft, DWG) to objectify oncological infrastructure and current standard of care in spinal tumor treatment in Germany.

METHODS

All DWG-members were contacted via the society's e-mail and asked to respond in anonymized form to a related questionnaire. Questions were asked regarding surgical specialty, type of institution involved, numbers of spinal procedures, as well as questions on treatment for primary tumors, whether the respondent belonged to a tumor center, decision-making procedures for surgery, and the type of procedure.

RESULTS

84 centers providing surgical treatment for spinal tumors in their departments were identified. 52.6% were carrying out more than 500 spinal procedures per year. There was a significant association (P ≤ 0.05) between the numbers of spinal surgeries, the number of treated tumor patients per year, the organisation in a tumor center and the treatment of primary tumors. 76% are part of a local tumor center for interdisciplinary decision making (i.e.surgical treatment and adjuvant therapy). 74% of the institutions stated that conventional postoperative radiotherapy is standardly administered in the case of secondary lesions, with 24% of them referring patients to external services for radiotherapy.

CONCLUSION

In spite of often large numbers of spinal operations, the centers perform relatively small numbers of tumor operations, particularly for primary tumors. A nearly three-quarter majority of the departments are integrated into interdisciplinary tumor care. However, there is a marked number that do not belong to an interdisciplinary organisation. Further advances in multidisciplinarity and oncology training are a continuous issue to increase treatment quality in spinal tumor patients.

Spinal intradural extramedullary cavernous hemangioma

Spinal intradural extramedullary cavernous hemangiomas are very rare. Mixed intensities on T1- andT2-weighted images due to repeated hemorrhages and poor to absent contrast-enhancement are the most common imaging features of the disease allowing accurate differentiation from the far more frequent meningiomas and schwannomas of similar location.

A rare case of concomitant cervical disc herniation and intradural meningioma treated with one-stage posterior surgery

STUDY DESIGN

Case report.

PURPOSE

To present a rare case of cervical disc herniation concomitant with intradural meningioma which was successfully treated using a single one-stage posterior surgery of tumor resection and transdural discectomy. Coexistence of symptomatic disc herniation and intra-spinal tumor in the same cervical segment is extremely rare. Usually, two-stage anterior and posterior surgeries are needed to treat two conditions, respectively. One-stage posterior surgery to treat two pathologies simultaneously has not been reported in the literature.

METHODS AND RESULTS

A 76-year-old man presented with leg weakness and numbness for 6 months and left arm pain for 2 months. Contrast MR imaging revealed C3/4 intervertebral disc herniation and a hyperintense intradural lesion at the right portion of C3 canal. A one-stage posterior surgery, including C3/4 laminectomy, intradural tumor resection, transdural C3/4 discectomy, and C3/4 lateral mass instrumentation and fusion, was performed to treat two distinct pathologies together. The patient's arm pain and numbness disappeared right after the surgery and symptoms of myelopathy fully recovered at 6-month follow-up. Histological studies confirmed a herniated disc and a meningioma.

CONCLUSION

In rare case, intradural tumor coexists with cervical disc herniation. When suspicious findings were noticed, or clinical symptoms cannot be fully explained, contrast MR imaging is helpful in differential diagnosis. Microscopic transdural discectomy is safe, and could be used as an optional procedure for cervical disc herniation in some cases.

Experience of operative treatment in 27 patients with intraspinal neurilemmoma

To investigate the clinical outcomes of posterior laminectomy on intraspinal neurilemmoma. Twenty-seven patients with intraspinal neurilemmoma admitted to the Second People's Hospital of Changzhou Affiliated to Nanjing Medical University from January 2010 to October 2015 were selected, and they received posterior laminectomy, and there were 5 patients whose nerve root and tumor were removed together because they could not be separated; 17 patients receiving total laminectomy or semi-laminectomy combined with facetectomy on the affected side were treated with spinal dynamic pedicle screw fixation or replantation of lamina or bone graft fusion and internal fixation. The patients were followed up regularly to observe the clinical outcomes after operation. The spinal stability and bone graft fusion were observed via X-ray film in review. Whether there was tumor recurrence was observed via MRI in review according to the individual condition. The operation time was 2.5–8 h (4.2 h on average). The intraoperative blood loss was 420–1,500 ml (760 ml on average). Tumors in 26 patients were totally resected, and tumor in 1 patient was partially resected due to tumor tissue invasion against the anterior sacral vascular plexus. All patients were pathologically confirmed as neurilemmoma after operation. Ten patients suffered from cerebrospinal fluid leakage in different degrees after operation. During the follow-up for 6–75 months after operation, clinical symptoms and neurological functions of all patients were significantly improved; there was 1 case of tumor residual and no recurrence. During the follow-up, the internal fixation in all patients receiving internal fixation of spine was stable with no vertebral instability. Posterior laminectomy can achieve satisfactory clinical outcomes in the treatment of intraspinal neurilemmoma. Internal fixation is needed to reestablish spinal stability during operation for those patients with great damage to spinal stability.