Nonenhancing intramedullary astrocytomas and other MR imaging features: a retrospective study and systematic review

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.

Imaging of Adult Malignant Soft Tissue Tumors of the Spinal Canal: A Guide for Spine Surgeons

BACKGROUND

Malignant soft tissue spinal canal tumors compromise 20% of all spinal neoplasms. They may be primary or metastatic lesions, originating from a diverse range of tissues within and surrounding the spinal canal. These masses can present as diverse emergencies such as secondary cauda equina syndrome, vascular compromise, or syringomyelia. Interpretation of malignant soft tissue spinal canal tumors imaging is an essential for non-radiologists in the setting of emergencies. This task is intricate due to a great radiologic pattern overlap among entities.

METHODS

We present a step-by-step strategy that can guide nonradiologists identify a likely malignant soft tissue lesion in the spinal canal based on imaging features, as well as a review of the radiologic features of malignant soft tissue spinal canal tumors.

RESULTS

Diagnosis of soft tissue spinal canal malignancies starts with the identification of the lesion's spinal level and its relationship to the dura and medulla. The second step consists of characterizing it as likely-malignant based on radiological signs like a larger size, ill-defined margins, central necrosis, and/or increased vascularity. The third step is to identify additional imaging features such as intratumoral hemorrhage or cyst formation that can suggest specific malignancies. The physician can then formulate a differential diagnosis. The most encountered malignant soft tissue tumors of the spinal canal are anaplastic ependymomas, anaplastic astrocytomas, metastatic tumors, lymphoma, peripheral nerve sheath tumors, and central nervous system melanomas. A review of the imaging features of every type/subtype of lesion is presented in this work. Although magnetic resonance imaging remains the modality of choice for spinal tumor assessment, other techniques such as dynamic contrast agent-enhanced perfusion magnetic resonance imaging or diffusion-weighted imaging could guide diagnosis in specific situations.

CONCLUSIONS

In this review, diagnostic strategies for several spinal cord tumors were presented, including anaplastic ependymoma, metastatic spinal cord tumors, anaplastic and malignant astrocytoma, lymphoma, malignant peripheral nerve sheath tumors , and primary central nervous system melanoma. Although the characterization of spinal cord tumors can be challenging, comprehensive knowledge of imaging features can help overcome these challenges and ensure optimal management of spinal canal lesions.

Intramedullary pediatric low-grade glioma of the spine

PURPOSE

Pediatric intramedullary spinal cord low-grade gliomas (pLGGs) are rare diagnoses among central nervous system (CNS) tumors in the pediatric population. The classic presentation of the patients includes some degree of neurologic deficit, although many times the symptoms are vague which leads to delayed diagnosis.

MATERIAL AND METHODS

The first step in the diagnosis includes special parameters in spinal imaging, particularly magnetic resonance imaging (MRI), and surgical resection remains the cornerstone for both diagnosis and treatment. Yet, recent years advancement in molecular and genetic understanding of CNS tumors allows for better adjustment of the treatment and follow-up regimens. Based on postoperative status, adjuvant therapy may provide additional therapeutic advantage for some types of tumors.

CONCLUSION

Ultimately, patients have a very promising prognosis when treated appropriately in most of the cases of pediatric spinal cord LGG with continued advances arising. This manuscript summarizes the most contemporary evidence regarding clinical and treatment features of intramedullary pLGGs.

A novel lateral myelotomy approach for the treatment of lateral or ventrolateral spinal gliomas

OBJECTIVE

To describe a novel surgical approach in which myelotomy was performed lateral to the dorsal root entry zone (LDREZ), for the treatment of lateral or ventrolateral spinal intramedullary glioma.

METHODS

This study reviewed six patients with lateral or ventrolateral spinal intramedullary glioma who received surgical treatments by using myelotomy technique of LDREZ approach. The patient's clinical characteristics, magnetic resonance imaging (MRI) results, and follow-up outcomes were analyzed. The neurological function of patients before and after operation was assessed based on the Frankel scale system. The anatomical feasibility, surgical techniques, advantages and disadvantages of LDREZ approach were analyzed.

RESULTS

Myelotomy technique of LDREZ approach was employed in all 6 patients. Gross total resections were achieved in 4 patients, and 2 patients with astrocytoma (case 2, 6) underwent partial removal. The perioperative recovery was all smooth and all the patients were discharged on schedule. All the patients who suffered from neuropathic pain were relieved. After surgery, neurological function remained unchanged in 3 patients. 2 patients improved from Frankel grade B to C, and 1 patient deteriorated from Frankel grade D to C immediately after surgery and returned to Frankel grade D at 3 months follow-up. Regarding to the poor prognosis of high-grade glioma, the two cases with WHO IV glioma didn't achieve long survival.

CONCLUSION

LDREZ approach is feasible and safe for the surgical removal of lateral or ventrolateral spinal gliomas. This approach can provide a direct pathway to lateral or ventrolateral spinal gliomas with minimal damage to normal spinal cord.

Utility of the 2023 international MOGAD panel proposed criteria in clinical practice: An institutional cohort

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently defined demyelinating disorder with a rapidly evolving clinical spectrum. Recently, consensus criteria have been proposed (Banwell et al., 2023) to help with disease diagnosis. However, validation of the proposed criteria in real-life MOGAD patients is lacking. In this study, we applied the proposed criteria to an institutional cohort of MOG antibody-positive patients.

METHODS

A retrospective study was conducted at a tertiary neuroimmunology clinic from 2018 to 2023. Patients who had at least one core clinical feature of MOGAD and positive serum MOG antibody by cell-based assay were included. Demographics and clinical data were recorded and analyzed. Cases were divided into definite MOGAD, questionable MOGAD, and false-positive MOG antibody as determined by the treating neuroimmunology and/or neuro-ophthalmology specialists prior to applying the new MOGAD criteria by an independent investigator. We then calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the new criteria compared to the treating physicians' assessment.

RESULTS

A total of 27 patients were included of which, 19 (70.4%) were female, the average age of the sample was 44 +/- 15 years. High titer MOG antibody (≥ 1:100) was found in 11 patients (40.7%); low titer (< 1: 100) in 13 (48.1%), and unreported titer in 3 patients. As determined by expert opinion; 18 (66.7%) were identified as definitive MOGAD, 6 (22.2%) as false-positive MOG antibody, and 3 (11.1%) as questionable MOGAD. All 18 patients identified by clinicians as definite MOGAD met the new 2023 criteria. Of the 9 patients with questionable MOGAD or false-positive MOG antibody, four patients met the 2023 MOGAD criteria. Those four patients had the following final diagnoses: CNS vasculitis, primary progressive MS with activity and progression, pseudotumor cerebri, and bevacizumab-induced anterior ischemic optic neuropathy in the setting of paraneoplastic retinopathy. Compared to clinician assessment, applying the 2023 MOGAD criteria to our institutional cohort yielded a sensitivity of 100%, a specificity of 55.5%, a positive predictive value of 81.5% and a negative predictive value of 100%.

CONCLUSION

These findings suggest that the 2023 MOGAD criteria are highly sensitive for detection of definite MOGAD but has modest specificity. A number of MOGAD mimickers can resemble the core clinical events of MOGAD and share similar supportive clinical and MRI features. Clinicians should practice caution when evaluating patients with low titer MOG antibody even if they meet the additional supportive features proposed by the 2023 criteria. Further studies are needed to evaluate the 2023 criteria in larger cohorts and in the pediatric population.

Radiological characterization of pediatric intramedullary astrocytomas: Do they differ from adults?

Introduction

The incidence of intramedullary spinal cord tumors ranges from 2 to 4% of all central nervous system tumors. Only 6-8% are astrocytomas. The gold standard to diagnose a spinal cord tumor is the spinal cord MRI in toto. Specific radiological criteria orient the diagnosis of the intradural intramedullary lesion. Most of the authors studied adult populations of astrocytomas. However, pediatric astrocytomas present certain particularities.

Research question

This work aims to determine if the usual radiological criteria of intramedullary astrocytomas (IMAs) are different depending on the patient's age.

Material & methods

We evaluated the radiological features of IMAs in adult and pediatric groups through a retrospective study.

Results

We collected 31 patients with IMAs (11 children and 20 adults). We observed some trends but we did not highlight any statistically significant difference between all the radiological criteria studied (sagittal and axial spinal cord localization, T1-and T2-weighted characteristics, contrast uptake, infiltrating character, presence of necrosis, heterogeneous lesion, necrotic, hemorrhagic, presence of edema) and the patient's age.

Discussion & conclusion

Given the rarity of IMAs and the lack of large specific pediatric studies, it seems essential to routinely report all cases encountered and create multicentric pediatric databases to draw more robust conclusions.

Imaging of pediatric spine and spinal cord tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper

Childhood spinal tumors are rare. Tumors can involve the spinal cord, the meninges, bony spine, and the paraspinal tissue. Optimized imaging should be utilized to evaluate tumors arising from specific spinal compartments. This paper provides consensus-based recommendations for optimized imaging of tumors arising from specific spinal compartments at diagnosis, follow-up during and after therapy, and response assessment.

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.

Clinical and Imaging Characteristics of Non-Neoplastic Spinal Lesions: A Comparative Study with Intramedullary Tumors

The features of non-neoplastic lesions are often similar to those of intramedullary tumors, and a differential diagnosis is challenging to obtain in some cases. A surgical biopsy, which is performed on highly invasive tumors, should be avoided in cases of non-neoplastic lesions. Therefore, an accurate diagnosis is important prior to treatment. We evaluated 43 patients suspected of having spinal cord tumors and, finally, were diagnosed with non-neoplastic intramedullary lesions via magnetic resonance imaging. The patients commonly presented with myelitis. The patients with non-neoplastic neurological diseases had a significantly shorter symptom duration than those with intramedullary astrocytomas. The proportion of patients with non-neoplastic neurological diseases who presented with lesions at the cervical spinal level and focal lesions on axial imaging but without a spinal cord enlargement was significantly higher than that of patients with intramedullary astrocytomas. The current study aimed to distinguish spinal cord tumors from non-neoplastic intramedullary lesions based on their distinct features.

Magnetic Resonance Imaging Findings of Intraspinal Tuberculoma in Children

Background and Purpose

Intraspinal tuberculoma is a rare disease in children, and its imaging findings have been described in only a few case reports. This study aimed to investigate the magnetic resonance imaging (MRI) features of pediatric intraspinal tuberculoma and to explore the possible pathogenesis of the disease.

Materials and Methods

The clinical and MRI data of 24 child patients with intraspinal tuberculoma (such as 6 cases of intramedullary tuberculoma, 8 cases of intradural extramedullary tuberculoma, and 10 cases of epidural tuberculoma) were retrospectively analyzed. All patients underwent plain and contrast-enhanced MR scans. The diagnosis was confirmed by surgical pathology or by antituberculous treatment and follow-up data.

Results

Intramedullary tuberculoma had a round shape, while intradural extramedullary tuberculoma and epidural tuberculoma presented long-fusiform or en plaque shapes. Regarding MRI signals, intramedullary tuberculoma and extramedullary tuberculoma were mainly isointense on T1-weighted imaging (T1WI) and hypointense or isointense on T2WI. Rim enhancement was observed in intramedullary tuberculoma, and marked homogeneous enhancement was dominant in extramedullary tuberculoma. Ten (10/24) tuberculomas occurred during antituberculous therapy, with intradural extramedullary tuberculoma accounting for 7 cases (7/8), which was significantly more frequent than intramedullary tuberculoma (1/6) or epidural tuberculoma (2/10).

Conclusion

MRI is important in the diagnosis of intraspinal tuberculoma, which is characterized by isointensity on T1WI, isointensity, or hypointensity on T2WI, and rim or obvious homogeneous enhancement. Some intraspinal tuberculomas, especially intradural extramedullary tuberculomas, might be associated with the “paradoxical response” mechanism during the tuberculosis 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.

A rare brainstem anaplastic astrocytoma

BACKGROUND

Anaplastic astrocytoma (AA) is rarely observed in the brainstem and the clinical symptoms and imaging manifestations vary, which present a great challenge to accurate clinical diagnosis.

CASE DESCRIPTION

A 56-year-old woman, with a month-long history of nausea and vomiting, was first diagnosed with acute cerebral infarction and demyelinating disease. The patient showed negative results on enhanced magnetic resonance and ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography, and the clinical symptoms were not typical, leading to early misdiagnosis.

CONCLUSION

Finally, the patient was diagnosed with AA by pathological biopsy.

Intradural Pediatric Spinal Tumors: An Overview from Imaging to Novel Molecular Findings

Pediatric spinal tumors are rare and account for 10% of all central nervous system tumors in children. Onset usually occurs with chronic nonspecific symptoms and may depend on the intra- or extradural neoplastic location. Meningiomas, schwannomas, and neurofibromas are the most common intradural-extramedullary lesions, while astrocytomas and ependymomas represent the majority of intramedullary tumors. The new molecular discoveries regarding pediatric spinal cancer currently contribute to the diagnostic and therapeutic processes. Moreover, some familial genetic syndromes can be associated with the development of spinal tumors. Currently, magnetic resonance imaging (MRI) is the standard reference for the evaluation of pediatric spinal tumors. Our aim in this review was to describe the imaging of the most frequent intradural intra/extramedullary pediatric spinal tumors and to investigate the latest molecular findings and genetic syndromes.

Intramedullary spinal cord tumors: A retrospective multicentric study

CONTEXT

Intramedullary tumors are neoformations taking part on the spinal cord, and they are a rare pathology. Due to the rarity of such lesions, clinical studies take years to ensure a decent feedback with a significant number of cases.

DESIGN

Our study is retrospective and descriptive.

PARTICIPANTS

We share a Tunisian multicentric experience of 27 years through a retrospective study of 120 cases of spinal cord tumors that have been operated in six different centers.

OUTCOME MEASURES

The clinical, radiological, and histological findings have been analyzed along with postoperative results and tumoral progression so that we could conclude to some factors of prognosis concerning the management of these tumors.

RESULTS

The mean age of our patients is 33.84 years. We had 57 males and 63 females. The most frequent revealing symptom was motor trouble presented as frequent as 77.5% of the patients. Glial tumors were represented in 81 of the cases (67.5%) and nonglial by 39 cases (32.5%). Glial tumors we found were essentially 39 ependymomas and 35 astrocytomas. Surgical resection is key in the management of these lesions; the quality of tumoral resection was a significant factor of disease progression as subtotal resection is correlated to more important progression than total one.

CONCLUSION

We conclude this work with some statements. In terms of functional results, age is not a significant factor. Presurgical functional state, the histological type, and the extent of surgical resection are the important factors.

Clinical, radiological and molecular characterization of intramedullary astrocytomas

Intramedullary astrocytomas (IMAs) are rare tumors, and few studies specific to the molecular alterations of IMAs have been performed. Recently, KIAA1549-BRAF fusions and the H3F3A p.K27M mutation have been described in low-grade (LG) and high-grade (HG) IMAs, respectively. In the present study, we collected clinico-radiological data and performed targeted next-generation sequencing for 61 IMAs (26 grade I pilocytic, 17 grade II diffuse, 3 LG, 3 grade III and 12 grade IV) to identify KIAA1549-BRAF fusions and mutations in 33 genes commonly implicated in gliomas and the 1p/19q regions. One hundred seventeen brain astrocytomas were analyzed for comparison. While we did not observe a difference in clinico-radiological features between LG and HG IMAs, we observed significantly different overall survival (OS) and event-free survival (EFS). Multivariate analysis showed that the tumor grade was associated with better OS while EFS was strongly impacted by tumor grade and surgery, with higher rates of disease progression in cases in which only biopsy could be performed. For LG IMAs, EFS was only impacted by surgery and not by grade. The most common mutations found in IMAs involved TP53, H3F3A p.K27M and ATRX. As in the brain, grade I pilocytic IMAs frequently harbored KIAA1549-BRAF fusions but with different fusion types. Non-canonical IDH mutations were observed in only 2 grade II diffuse IMAs. No EGFR or TERT promoter alterations were found in IDH wild-type grade II diffuse IMAs. These latter tumors seem to have a good prognosis, and only 2 cases underwent anaplastic evolution. All of the HG IMAs presented at least one molecular alteration, with the most frequent one being the H3F3A p.K27M mutation. The H3F3A p.K27M mutation showed significant associations with OS and EFS after multivariate analysis. This study emphasizes that IMAs have distinct clinico-radiological, natural evolution and molecular landscapes from brain astrocytomas.

Radiologic-Histopathologic Correlation of Adult Spinal Tumors: A Retrospective Study

Aim:

Preoperatively performed magnetic resonance images (MRIs) are essential before treating spinal tumors surgically. This study aims to investigate the compatibility of MRI preliminary diagnosis and proven histopathologic diagnosis of consecutively operated 96 spinal tumors.

Material and Methods:

Medical records were retrospectively reviewed for all spinal tumors operated at our institute during a period of 6 years. One hundred and ten spinal tumors were detected. Fourteen tumors were excluded because they were not met our study criteria.

Results:

Ninety-six cases of spinal tumors were detected in 46 female and 50 male patients. The mean age was 49.3 ± 22.7 years. The most common symptom was radicular pain (88.6%). Histopathologic diagnoses were metastasis (n = 26), meningioma (n = 16), schwannoma (n = 15), ependymoma (n = 9), astrocytoma (n = 6), chronic nonspecific granulomatous infection (n = 4), lymphoma (n = 3), lipoma (n = 3), epidural tuberculosis abscess (Pott's disease) (n = 3), and other pathologies in 11 cases. Cervical spine was the less spinal region affected with metastases (P < 0.05). Thoracic spine was the most affected spinal region from meningioma (P < 0.05). Preoperatively, preliminary diagnosis on MRIs was proven with histopathologic examinations in 22 metastasis, 14 meningioma, 11 schwannoma, and all epidermoid cyst and lipoma cases. Despite the fact that MRI cannot diagnose all cases of spinal tumors, MRIs had a high accurate rate to diagnose the most common spinal neoplasms (69.8%).

Conclusions:

Metastases rarely occurred in cervical spine, whereas meningiomas were most likely to occur in thoracic spine. MRIs can help diagnose metastases and spinal benign lesions, whereas they failed to distinguish astrocytomas and lymphomas. Further prospective studies with large size are needed to support our results.

Surgical Management of Intramedullary Spinal Cord Tumors

Intramedullary spinal cord tumors (IMSCT) comprise a rare subset of CNS tumors that have distinct management strategies based on histopathology. These tumors often present challenges in regards to optimal timing for surgery, invasiveness, and recurrence. Advances in microsurgical techniques and technological adjuncts have improved extent of resection and outcomes with IMSCT. Furthermore, adjuvant therapies including targeted immunotherapies and image-guided radiation therapy have witnessed rapid development over the past decade, further improving survival for many of these patients. In this review, we provide an overview of types, epidemiology, imaging characteristics, surgical management strategies, and future areas of research for IMSCT.

Primary Spinal Astrocytomas: A Literature Review

Primary spinal astrocytoma is a subtype of glioma, the most common spinal cord tumor found in the intradural intramedullary compartment. Spinal astrocytomas account for 6-8% of all spinal cord tumors and are primarily low grade (World Health Organization grade I (WHO I) or WHO II). They are seen in both the adult and pediatric population with the most common presenting symptoms being back pain, sensory dysfunction, or motor dysfunction. Magnetic Resonance Imaging (MRI) with and without gadolinium is the imaging of choice, which usually reveals a hypointense T1 weighted and hyperintense T2 weighted lesion with a heterogeneous pattern of contrast enhancement. Further imaging which may aid in surgical planning includes computerized tomography, diffusion tensor imaging, and tractography. Median survival in spinal cord astrocytomas ranges widely. The factors most significantly associated with poor prognosis and shorter median survival are older age at initial diagnosis, higher grade lesion based on histology, and extent of resection. The mainstay of treatment for primary spinal cord astrocytomas is surgical resection, with the goal of preservation of neurologic function, guided by intraoperative neuromonitoring. Adjunctive radiation has been shown beneficial and may increase overall survival. The role of adjunctive chemotherapy is employed, however, its benefit has not been clearly defined. Primary spinal cord astrocytomas are rare and challenging to treat. The gold standard treatment is surgical resection. Second-line treatments include radiation and chemotherapy, although, the optimal regimen for adjunctive therapy has not yet been clearly defined.

MR imaging features of spinal pilocytic astrocytoma

Background

The purpose of this retrospective review is to determine the MR imaging features of pilocytic astrocytoma (PA) in the spinal cord to help neuroradiologists preoperatively differentiate PA from other intramedullary tumors.

Methods

Neuro-oncology database review revealed 13 consecutive patients with a pathological spinal PA diagnosis and availability of preoperative MR imaging. Three patients had preoperative diffusion-weighted MR imaging. Demographics and conventional and diffusion MR imaging records were retrospectively evaluated.

Results

Among 13 cases of spinal PA, six PAs were located in the cervical region, 4 in the cervical-thoracic region, and 3 in the thoracic region. The average length of vertebral segments involved for the tumors were 4.7 ± 4.6 segments. Six tumors had associated syringomyelia. Eight PAs were located eccentrically in the spinal cord, and eleven had well-defined margins. Eight tumors (61.5%) were intermixed cystic and solid. All were contrast-enhanced, and 53.8% of all PAs showed focal nodule enhancement of the solid components. Two PAs showed intratumoral hemorrhages, and only one demonstrated cap sign. The ADC values (n = 3) of the tumors were 1.40 ± 0.28 × 10^− 3 mm²/s (min–max: 1.17–1.71 × 10^− 3 mm²/s).

Conclusions

PA should be considered in the differential diagnosis of intramedullary tumors that occur in the cervical and thoracic regions. Eccentric growth pattern, well-defined margin, intermixed cystic and solid appearance, focal nodular enhancement of solid components and syringomyelia are relatively frequent features. Relatively high ADC values compared with normal-appearing spinal cord parenchyma are common in spinal PA.

3T proton MR Spectroscopy evaluation of spinal cord lesions

Objective:

The objective of this study was to evaluate intramedullary spinal cord lesions using magnetic resonance spectroscopy and correlate the results with histo-pathological examination (HPE).

Materials and Methods:

Approval for this study was obtained from our institute ethical committee. Overall, 50 patients were recruited (29 male and 21 female), with a maximum age of 53 years and minimum age of 7 years. The mean age group of the study was 33 years. Standard magnetic resonance imaging (MRI) spine was done on a Siemens Skyra 3Tesla MRI scanner. MR Spectroscopy (MRS) was performed for all patients with intramedullary spinal lesions after getting written consent. It was performed using single-voxel method. The change in the metabolite peak was observed in each case and the results were compared with HPE. These collected data were analyzed using SPSS 16.0 version. Descriptive statistics, frequency analysis, and percentage analysis were used for categorical variables; and for continuous variables, mean and standard deviation were analyzed. McNemar's test was used to find the significance between conventional MRI MRS. In the above statistical tool, the probability value 0.05 is considered as significant level.

Results:

From our study, we observed that by applying routine MRI sequences alone, we could only detect around 58% of the cases correctly. However, when MRS was done along with the conventional MR imaging, the number of cases detected significantly increased to 84%. By applying McNemar's test and comparing the conventional MRI and MRS with HPE, it was found that statistically significant difference exists with P value of 0.007.

Conclusion:

MRS of the spinal cord is a promising tool for research and diagnosis because it can provide additional information complementary to other non-invasive imaging methods. It is an emerging tool and adds new biomarker information for characterization of spinal cord tumors, to differentiate benign from malignant lesions and to prevent unnecessary biopsies and surgeries.

The Slowly Enlarging Ventriculus Terminalis

Background

A cerebral spinal fluid (CSF) cavity within the conus medullaris has been described by the term ventriculus terminalis (VT) or the fifth ventricle. The finding of a VT on MRI imaging of the lumbar spine is often incidental but may be found in patients with low back pain or neuromuscular deficits. These lesions, when identified, are thought to regress or remain stable in terms of size, although some have been described to enlarge in the presence of post-traumatic meningeal hemorrhages or deformities of the vertebral canal.

Case Report

We describe a case of a slowly growing VT in a patient with progressing lower limb weakness without any history or imaging findings of trauma or spinal canal abnormalities.

Conclusions

We present an intriguing case of a slowly growing VT in a woman with progressive neurological symptoms. Surgical fenestration provided complete symptomatic relief and follow-up imaging two years after surgery demonstrated no evidence of recurrence. This, to our knowledge, is the first described case of a slowly enlarging VT independent of any other imaging findings.

Neuroimaging of spine tumors

Intramedullary, intradural/extramedullary, and extradural spine tumors comprise a wide range of neoplasms with an even wider range of clinical symptoms and prognostic features. Magnetic resonance imaging (MRI), commonly used to evaluate the spine in patients presenting with pain, can further characterize lesions that may be encountered on other imaging studies, such as bone scintigraphy or computed tomography (CT). The advantage of the MRI is its multiplane capabilities, superior contrast agent resolution, and flexible protocols that play an important role in assessing tumor location, extent in directing biopsy, in planning proper therapy, and in evaluating therapeutic results. A multimodality approach can be used to fully characterize the lesion and the combination of information obtained from the different modalities usually narrows the diagnostic possibilities significantly. The diagnosis of spinal tumors is based on patient age, topographic features of the tumor, and lesion pattern, as seen at CT and MRI. The shift to high-end imaging incorporating diffusion-weighted imaging, diffusion tensor imaging, magnetic resonance spectroscopy, whole-body short tau inversion recovery, positron emission tomography, intraoperative and high-field MRI as part of the mainstream clinical imaging protocol has provided neurologists, neuro-oncologists, and neurosurgeons a window of opportunity to assess the biologic behavior of spine neoplasms. This chapter reviews neuroimaging of spine tumors, primary and secondary, discussing routine and newer modalities that can reduce the significant morbidity associated with these neoplasms.

Cervical intramedullary schwannoma mimicking a glioma

We present a case of a cervical intramedullary schwannoma (IS), which resembled a glioma on radiology. Somatic and root pain, the most common presenting complaints of IS, were lacking in our patient, and the characteristic magnetic resonance finding of an enhancing thickened nerve root in IS, was absent in our case. Preoperative diagnosis of a cervical IS is not always possible. Complete tumor resection is the ideal treatment for IS. Intraoperative frozen section can be a useful for decision making though the tumor-cord plane will ultimately decide if the tumor can be radically excised.

Spinal cord astrocytoma mimicking multifocal myelitis

INTRODUCTION

Differential diagnosis of acute/subacute intrinsic spinal cord lesions can be challenging. In addition, intramedullary neoplasms typically show gadolinium enhancement, mass effect, and cord expansion.

CASE REPORT

We report a patient with spinal cord and brain stem lesions resembling multifocal myelitis. Magnetic resonance imaging showed no spinal cord enlargement or gadolinium enhancing. Treatment of myelitis was undertaken without stopping the progression of the disease. Biopsy was made and led to a histological diagnosis of astrocytoma.

DISCUSSION

Astrocytoma must remain as a possible diagnosis of spinal cord lesions, even without typical characteristics of neoplasms. Furthermore, biopsy should always be considered when diagnosis is uncertain.

Pediatric low-grade gliomas: how modern biology reshapes the clinical field

Low-grade gliomas represent the most frequent brain tumors arising during childhood. They are characterized by a broad and heterogeneous group of tumors that are currently classified by the WHO according to their morphological appearance. Here we review the clinical features of these tumors, current therapeutic strategies and the recent discovery of genomic alterations characteristic to these tumors. We further explore how these recent biological findings stand to transform the treatment for these tumors and impact the diagnostic criteria for pediatric low-grade gliomas.

Ventriculus terminalis in adults: unusual magnetic resonance imaging features and review of the literature

OBJECTIVE

The ventriculus terminalis (VT) in adults is a rare pathology. We report various MR imaging features of the adult VT.

MATERIALS AND METHODS

Ten patients were included in this retrospective review.. All patients had undergone magnetic resonance (MR imaging with a surface coil that used two different 1.5T MR systems. All patients had undergone initial and follow-up MR imaging with contrast enhancement using gadopentate dimeglumine. Three patients underwent additional MR imaging using the echocardiogram-gated spatial modulation of magnetization (SPAMM) technique. If a shift in tagging band during the systolic phase was less than half of the band space, it was defined as a "non-pulsatile fluid". Two neuroradiologists independently reviewed these images, while clinical symptoms and outcomes were statistically analyzed between the treated and non-treated group.

RESULTS

All cases presented an intramedullary cystic lesion in the conus medullaris and showed the same signal intensity as CSF. Three VTs had intracystic septation and cord edema, which were pathologically confirmed after surgery; two of these were associated with kyphotic deformity and spinal arteriovenous malformation. SPAMM-MRI of 3 patients demonstrated non-pulsatile fluid motion within the VT. In the treated group, clinical symptoms improved better than the non-treated group.

CONCLUSION

The adult VT shows some unusual imaging features, including septation, cord edema, and coexistence of a spinal AVM, as well as the typical findings. Surgical maneuvers may be considered as a treatment option in adult VT with progressive neurological symptoms.

Longitudinal extensive transverse myelitis--it's not all neuromyelitis optica

Longitudinal extensive transverse myelitis (LETM) is defined as a spinal cord lesion that extends over three or more vertebrae, as seen on MRI of the spine. The clinical presentation of a patient with LETM is often dramatic and can consist of paraparesis or tetraparesis, sensory disturbances, and gait, bladder, bowel and/or sexual dysfunction. LETM is a characteristic feature of neuromyelitis optica, but such spinal lesions can also occur in various other autoimmune and inflammatory diseases that involve the CNS--such as multiple sclerosis, sarcoidosis or Sjögren syndrome--or in infectious diseases with CNS involvement. Patients with a neoplastic disorder or traumatic spinal cord injury can also present with longitudinal spinal lesions. In this Review, the signs and symptoms that suggest various etiologies and differential diagnoses of LETM are described, and illustrated by educational case studies. The best therapeutic options for patients with each diagnosis are also discussed.