Imaging of Intraspinal Tumors

A comprehensive evaluation of imaging features in pediatric spinal gliomas and their value in predicting tumor grade and histology

PURPOSE

Pediatric spinal cord gliomas (PSGs) are rare in children and few reports detail their imaging features. We tested the association of tumoral grade with imaging features and proposed a novel approach to categorize post-contrast enhancement patterns in PSGs.

METHODS

This single-center, retrospective study included patients <21 years of age with preoperative spinal MRI and confirmed pathological diagnosis of PSG from 2000-2022. Tumors were classified using the 5th edition of the WHO CNS Tumors Classification. Two radiologists reviewed multiple imaging features, and classified enhancement patterns using a novel approach. Fisher's exact test determined associations between imaging and histological features.

RESULTS

Forty-one PSGs were reviewed. Thirty-four were intramedullary, and seven were extramedullary. Pilocytic astrocytoma was the most common tumor (39.02%). Pain and weakness were the most prevalent symptoms. Seven patients (17.07%) died. Cyst, syringomyelia, and leptomeningeal enhancement were associated with tumor grade. Widening of the spinal canal was observed only in low-grade astrocytomas. There was a significant association between tumor grade and contrast enhancement pattern. Specifically, low-grade PSGs were more likely to exhibit type 1A enhancement (mass-like, with well-defined enhancing margins) and less likely to exhibit type 1B enhancement (mass-like, with ill-defined enhancing margins).

CONCLUSION

PSGs display overlapping imaging features, making grade differentiation challenging based solely on imaging. The correlation between tumor grade and contrast enhancement patterns suggests a potential diagnostic avenue, requiring further validation with larger, multicenter studies. Furthermore, Low-grade PSGs display cysts and syringomyelia more frequently, and leptomeningeal enhancement is less common.

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.

Imaging Features of Intramedullary Spinal Cord Lesions with Histopathological Correlation

Purpose Most of the intramedullary spinal cord lesions have a component of insidious myelopathic changes at the time of diagnosis. Among the spinal cord lesions, intramedullary neoplasms are rare (25%). They represent 4 to 10% of all central nervous system tumors. But due to involvement of tracts, they are associated with significant neurological symptoms. Their imaging features can help early diagnosis and predict prognosis. We aim to narrow down differential diagnoses of intramedullary lesions based on imaging findings.

Materials and Methods This retrospective study included 40 patients as a sample that underwent magnetic resonance imaging spine at our institution (on 3T machine). Patient population had varied clinical complaints, ranging from headache, nausea, vomiting, motor weakness, bladder and bowel involvement, progressive paraparesis to paraplegia. Lesions were evaluated site, size, margin, associated cysts, signal intensity, enhancement, and associated syringohydromyelia.

Results This study obtained majority of the lesions to be ependymoma (15) and astrocytoma (11), followed by infection (4), hemangioblastoma (3), and metastasis (2). Five patients were either lost to follow-up or not operated on.

Conclusion Most of the intramedullary lesions were malignant and were showing postcontrast enhancement. Ependymomas were more frequently present in cervical region, central in location with well-defined margins and focal postcontrast enhancement. Among the total of 15 ependymomas, three cases were associated with neurofibromatosis-2. Ependymomas were more frequently associated with syringohydromyelia and peripheral hemorrhage (cap sign). Astrocytoma was more frequently seen in children, thoracic and eccentric in location with ill-defined margins. Enhancement in astrocytoma was dependent on the grade of tumor. Metastasis was a differential, with imaging characteristics dependent on type of primary. Intramedullary granuloma due to infection can also be confusing mimics of neoplasm. High-velocity signal loss due to flow voids is seen in the hemangioblastomas.

Primary Paraganglioma of the Spine: A Systematic Review of Clinical Features and Surgical Management in Cauda Equina vs Non-Cauda Equina Lesions

BACKGROUND

Primary spine paragangliomas are rare tumors. Surgical resection plays a role, but aggressive lesions are challenging. We reviewed the literature on primary spine paragangliomas.

METHODS

PubMed, Scopus, Web of Science, and Cochrane were searched upon the PRISMA guidelines to include studies on primary spine paragangliomas. Clinical-radiological features, treatments, and outcomes were analyzed and compared between cauda-equina vs non-cauda-equina tumors.

RESULTS

We included 143 studies comprising 334 patients. Median age was 46 years (range, 6-85). The most frequent symptoms were lower-back (64.1%) and radicular (53.9%) pain, and sympathetic in 18 patients (5.4%). Cauda-equina paragangliomas (84.1%) had frequently lumbar (49.1%) or lumbosacral (29%) locations. Non-cauda-equina tumors were mostly in the thoracic (11.4%), thoracolumbar (5.1%), and cervical (3.6%) spine. Median tumor diameter was 2.5cm (range, 0.5-13.0). Surgical resection (98.5%) was preferred over biopsy (1.5%). Decompressive laminectomy (53%) and spine fusion (6.9%) were also performed. Adjuvant radiotherapy was delivered in 39 patients (11.7%) with aggressive tumors. Post-treatment symptomatic improvement was described in 86.2% cases. Median follow-up was 19.5 months (range, 0.1-468.0), and 23 patients (3.9%) had tumor recurrences. No significant differences were found between cauda-equina vs non-cauda-equina tumors.

CONCLUSION

Surgical resection is effective and safe in treating primary spine paragangliomas; however, adjuvant treatments may be needed for aggressive lesions.

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.

Nontraumatic Spinal Cord Compression: MRI Primer for Emergency Department Radiologists

The occurrence of acute myelopathy in a nontrauma setting constitutes a medical emergency for which spinal MRI is frequently ordered as the first step in the patient's workup. The emergency department radiologist should be familiar with the common differential diagnoses of acute myelopathy and be able to differentiate compressive from noncompressive causes. The degree of spinal cord compression and presence of an intramedullary T2-hyperintense signal suggestive of an acute cord edema are critical findings for subsequent urgent care such as surgical decompression. Importantly, a delay in diagnosis may lead to permanent disability. In the spinal canal, compressive myelopathy can be localized to the epidural, intradural extramedullary, or intramedullary anatomic spaces. Effacement of the epidural fat and the lesion's relation to the thecal sac help to distinguish an epidural lesion from an intradural lesion. Noncompressive myelopathy manifests as an intramedullary T2-hyperintense signal without an underlying mass and has a wide range of vascular, metabolic, inflammatory, infectious, and demyelinating causes with seemingly overlapping imaging appearances. The differential diagnosis can be refined by considering the location of the abnormal signal intensity within the cord, the longitudinal extent of the disease, and the clinical history and laboratory findings. Use of a compartmental spinal MRI approach in patients with suspected nontraumatic spinal cord injury helps to localize the abnormality to an epidural, intradural extramedullary, or intramedullary space, and when combined with clinical and laboratory findings, aids in refining the diagnosis and determining the appropriate surgical or nonsurgical management.Online supplemental material is available for this article.^©RSNA, 2019.

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.

Ten-Segment Intramedullary Ependymoma and Whole Spinal Syringomyelia

BACKGROUND

Ten-segment intramedullary tumors are rare lesions in adults.

CASE DESCRIPTION

In this report, we describe the case of a 30-year-old woman who presented with a 2-year history of right lower limb numbness. Spinal magnetic resonance imaging showed an expansive 10-segment intramedullary lesion and syringomyelia. The final pathologic tests confirmed World Health Organization grade II ependymoma. She received a successful gross total tumorectomy with no obvious surgical-related complications.

CONCLUSIONS

The postoperative recovery is far beyond our expectations.

Intraspinal Canal Schwannoma with Extensive Calcification: Case Report and Literature Review

BACKGROUND

Schwannomas are the most common benign tumors in the intraspinal location, with slow-growing and nonaggressive features. Calcification is not a common histopathological and radiological feature in schwannoma.

CASE DESCRIPTION

We report the case of a 43-year-old man with soreness in the lower back, left buttock, and lower limb of 1 month's duration. On magnetic resonance imaging and computed tomography, an intradural mass with extensive calcification was found at the L1-L2 level. The tumor was completely resected, with sacrifice of 1 nerve root. Postoperatively, his symptoms were relieved, and no dysfunction of the lower limbs and sphincter was observed. Pathologically, the tumor was diagnosed as a schwannoma with extensive calcification. At the 7-month follow-up examination, no complaints were found.

CONCLUSION

Although intraspinal schwannoma with extensive calcification is rare, which increases the difficulty of an accurate diagnosis preoperatively, the tumor can be completely removed with or without excision of the nonfunctional nerve roots.