Tumefactive Multiple Sclerosis Research Articles

NIMG-82. DEVELOPMENT AND VALIDATION OF AN MRI-BASED DEEP LEARNING MODEL TO DIFFERENTIATEIDH-WILDTYPE GLIOBLASTOMA AND TUMEFACTIVE MULTIPLE SCLEROSIS

Abstract Clinical management of IDH wildtype glioblastoma (GBM) and tumefactive multiple sclerosis (tMS) is drastically different. GBM requires maximal safe resection followed by chemoradiation, while tMS outcome is worsened by surgery and radiotherapy. Noninvasive methods are needed to help with accurate diagnosis of tumor and non-tumor etiologies. To develop an MRI-based classification model, tMS subjects diagnosed prior to January 1, 2020, were matched to tMS by age at diagnosis, sex, index MRI date, and 2D/3D acquisition. Inclusion criteria included one cm minimal lesion size and pre-operative post-contrast T1 and T2 images available for analysis. A 3D-DenseNet121 was used to develop a classification model using prespecified parameters: 650 epochs, batch size 16, learning rate 10-3, cross-entropy loss, and AdamW optimizer. The stopping rule was defined as three sequential differences in epoch cross-entropy loss <0.02. Models were developed using both T1gd and T2, as well as from only T1gd and only T2. Training included 220 subjects (110 GBM, 110 tMS). A 2-stage validation design was used, which included both retrospective and prospective cohorts. Stage 1 consisted of 272 retrospective GBM (diagnosed prior to January 1, 2020). Stage 2 consisted of 69 and 34 prospective (diagnosed after January 1, 2020) GBM and tMS, respectively. External validation on the 272 retrospective GBM demonstrated accuracy of 91%, 84%, and 78% for T1gd+T2, T1gd only, and T2 only, respectively. External validation on the 69 prospective GBM demonstrated an accuracy of 87%, 64%, and 67% for T1gd+T2, T1gd only, and T2 only, respectively. The 34 prospective tMS demonstrated accuracy of 76%, 76%, and 82% for T1gd+T2, T1gd only, and T2 only, respectively. This shows the feasibility of deep learning to aid in differential diagnosis of brain lesions. Future work entails the integration of germline variants into the classification model, including variants associated with the risk of glioma or MS.

The diagnostic challenge of differentiating Tumefactive Multiple Sclerosis (TMS) from other brain lesions: a case report and literature review on a rare subtype of MS

Introduction and Importance: This case report is a clinical diagnosis walk through of a rare subtype of Multiple sclerosis (MS). It gives an overview of how Tumefactive multiple sclerosis (TMS) is systematically narrowed down as the definitive diagnosis. Case Presentation: Our 29 year old male patient presented to the emergency department. He collapsed after experiencing pain over his right frontotemporal region followed by a seizure witnessed by his family. Magnetic Resonance Imaging of the brain displayed a diffuse enlargement and abnormal T2 weighted and FLAIR hyperintense signals in the diagnostic impressions described by the radiologist of the right temporoparietal region. Clinical Discussion: Liquefactive Multiple Sclerosis, also known as tumefactive multiple sclerosis or Marburg-type multiple sclerosis, is a rare subtype of the neurological disorder that can be difficult to diagnose. Unlike the traditional form of Multiple sclerosis (MS), Tumefactive multiple sclerosis (TMS) can present as a brain tumor and must be diagnosed with a biopsy rather than via magnetic resonance imaging (MRI) and clinical findings alone. Patients can typically present with headache, cognitive abnormalities, mental confusion, aphasia, apraxia, seizures, and weakness. Here, we discuss the presentation, disease diagnosis process and patient management. Conclusion: The patient was stabilized and discharged with a referral to the neurosurgery and neurology departments for outpatient consultation for future clinical management and treatment of their condition.

Targeted proteomics of cerebrospinal fluid in treatment naïve multiple sclerosis patients identifies immune biomarkers of clinical phenotypes

Multiple sclerosis (MS) is an inflammatory demyelinating disease with heterogeneous clinical presentations and variable long-term disability accumulation. There are currently no standard criteria to accurately predict disease outcomes. In this study we investigated the cross-sectional relationship between disease phenotype and immune-modulating cytokines and chemokines in cerebrospinal fluid (CSF). We analyzed CSF from 20 DMT-naïve MS patients using Olink Proteomics’ Target 96 Inflammation panel and correlated the resulting analytes with respect to (1) disease subtype, (2) patient age and sex, (3) extent of clinical disability, and (4) MRI segmental brain volumes. We found that intrathecal IL-4 correlated with higher Expanded Disability Status Scale (EDSS) scores and longer 25-foot walk times, and CD8A correlated with decreased thalamic volumes and longer 9-hole peg test times. Male sex was associated with higher FGF-19 expression, and Tumefactive MS with elevated CCL4. Several inflammatory markers were correlated with older age at the time of LP. Finally, higher intrathecal IL-33 correlated with increased MS lesion burden and multi-compartment brain atrophy. This study confirms immune heterogeneity underlying CSF profiles in MS, but also identifies several inflammatory protein biomarkers that may be of use for predicting clinical outcomes in future algorithms.

Intra-arterial Melphalan as Targeted Therapy for Tumefactive Multiple Sclerosis Lesions.

Intra-arterial Melphalan as Targeted Therapy for Tumefactive Multiple Sclerosis Lesions.

Tumefactive Multiple Sclerosis: The Lethal Chameleon.

Tumefactive multiple sclerosis is an uncommon variant of multiple sclerosis that presents a substantial diagnostic challenge due to its potential to resemble the clinical and radiological characteristics of other central nervous system (CNS) pathologies, including neoplasms, granulomatous diseases, abscesses and vasculitis.Despite the fact that multimodal imaging studies may help narrow the differential diagnosis, a biopsy is often required to reach a definitive diagnosis and should not be delayed.Awareness of this condition among non-neurologists is critical since a timely and accurate diagnosis prompts aggressive immunomodulatory treatments that may delay a second demyelinating event or progression to clinically definite multiple sclerosis.

The Role of B-cell Therapy in the Treatment of Tumefactive Multiple Sclerosis: A Retrospective Cohort Study (P3-6.007)

The Role of B-cell Therapy in the Treatment of Tumefactive Multiple Sclerosis: A Retrospective Cohort Study (P3-6.007)

Tumefactive Multiple Sclerosis: A Mimicker of Intracranial Space-Occupying Lesions

Abstract: A chronic disease of CNS, Multiple sclerosis is characterized by inflammation and demyelination with axonal injury affecting upper motor neurons of brain or spinal cord. Tumefactive multiple sclerosis is a rare form of MS which mimics intracranial tumor-like space-occupying lesions on radiography. A 25-year old gentleman presented 2-month history of gradual onset difficulty in walking, slurring of speech and double vision. The patient had an ataxic gait accentuated by tandem walking with tendency to fall towards right and a negative Romberg’s sign. There was dysarthria and signs of cerebellar lesion present on the right side. Muscle tone was normal in upper limbs but increased (spasticity) in lower limbs bilaterally. Power was normal but deep tendon reflexes were exaggerated in all 4 limbs with bilateral up-going plantar reflex. MRI scan of the brain demonstrated tumour-like tumefactive lesions in the right cerebellum, right pons and the left subcortical region with no post-contrast enhancement of these lesions. MRI of whole spine demonstrated subtle hyperintense signals in the cervical spine. He had a past history of transverse myelitis 2 years ago with full clinical recovery with oral steroids. He was diagnosed with Tumefactive Multiple Sclerosis and started on corticosteroid therapy resulting in dramatic improvement.

NIMG-26. DIFFERENTIATION OF IDH-WILDTYPE GLIOBLASTOMA AND TUMEFACTIVE MULTIPLE SCLEROSIS USING PRE-OPERATIVE BRAIN MRI AND DEEP LEARNING: RIGOROUS AND UNBIASED EXPERIMENTAL DESIGN AND ANALYTICAL APPROACH

Abstract Clinical management of IDH wildtype glioblastoma (GBM) and tumefactive multiple sclerosis (tMS) is drastically different. GBM requires maximal safe resection followed by chemoradiation, while tMS outcome is worsened by surgery and radiotherapy. Misdiagnosis of brain lesions may expose patients to unnecessary anxiety, surgery, or radiotherapy. Noninvasive methods to help with accurate diagnosis of tumor and non-tumor etiologies are needed. tMS subjects were identified by the Mayo Clinic Center for Multiple Sclerosis and Autoimmune Neurology (CMSAN). GBM subjects were matched to tMS by age at diagnosis, index MRI date, and sex. Inclusion criteria included one cm minimal lesion size and pre-operative post-contrast T1 and T2 images available for analysis. To identify potential experimental design bias, MRI technology and clinical characteristics were compared across groups. A 3D-DenseNet121 was used to develop a classification model using prespecified parameters: 600 epochs, batch size 16, learning rate 10-3, cross entropy loss, and AdamW optimizer. The stopping rule was defined as three sequential epoch cross entropy loss < 0.02. Five-fold cross validation (CV) was utilized to obtain an unbiased estimate of predictive performance (overfitting) and sensitivity of the 3D-DenseNet121 algorithm was evaluated. 224 subjects (114 GBM, 110 tMS) were analyzed: 40% male, median age 46. After one round of CV, the average unbiased estimate of sensitivity and specificity for predicting GBM from the final classification model was 0.86 and 0.73, respectively. To assess the reproducibility of the deep learning algorithm (3D-DenseNet121), the exact same CV folds were rerun resulting in average sensitivity and specificity of 0.82 and 0.75, respectively. Obtaining unbiased estimates of model performance using internal validation is critical before evaluating a final model on an external dataset. Understanding sensitivity of a deep learning algorithm is important for model validity. Differentiation of GBM and tMS appears reasonable with MRI; external validation is in progress.

Parakinesia Brachialis Oscitans in a Patient With a First Manifestation of Multiple Sclerosis

ObjectivesParakinesia brachialis oscitans (PBO) is the involuntary movement of an otherwise paretic upper limb triggered by yawning. We describe the first case of PBO in a patient with a first manifestation of tumefactive multiple sclerosis (MS).MethodsA 35-year-old man presented to the emergency department with a first episode of generalized seizure. Neurologic examination revealed left-sided spastic hemiparesis, predominantly affecting his upper limb. Brain MRI showed a tumefactive right hemisphere lesion consistent with demyelination. CSF did not document unmatched oligoclonal bands.ResultsTwo weeks after admission and, despite being unable to voluntarily raise his left arm, the patient noticed a repeated and reproducible involuntary raise of this limb upon yawning, consistent with PBO. In the following weeks, the phenomenon diminished both in frequency and movement amplitude alongside motor recovery. An MRI performed 2 months later showed progression of the demyelinating lesion load and confirmed a diagnosis of MS.DiscussionPBO is an example of autonomic voluntary motor dissociation and reflects the interplay between loss of cortical inhibition of the cerebellum in the setting of functional spinocerebellar pathways. Clinicians should be aware of this transient phenomenon which should not be mistaken as a chronic movement disorder or focal epileptic seizures.

Tumefactive demyelinating disorders as stroke mimics: Description of cases and systematic review of the literature.

tumefactive multiple sclerosis (TmMS) is a rare subtype of a demyelinating disease that develops over time. Cases of hyperacute presentations mimicking cerebrovascular disorders have been reported; however, detailed clinical and demographic data are lacking. this study aimed to systematically review the literature on tumefactive demyelinating disorders presenting as strokes. After screening the PubMed, PubMed Central, and Web of Science databases, 39 articles describing 41 patients were identified, including 2 historical patients from our center. 23 (53.4%) patients were diagnosed with multiple sclerosis variants (vMS), 17 (39.5%) with inflammatory demyelinating variants (vInf), and 3 with tumors; however, only 43.5% of cases were verified histologically. In subgroup analysis, vMS differed from vInf in several aspects. Inflammatory cerebral spinal fluid parameters, including pleocytosis, proteinorachia was more commonly observed in vInf [11 (64.7%) vs. 1 (5.2%), P=0.001 and 13/17 (76.4%) vs. 6/23 (31.5%), P=0.02] than that in vMS. Neurological deterioration and fatal outcomes were more commonly observed in vInf [13/17 (76.4%) vs. 7/23 (30.4%), P=0.003, and 11/17 (64.7%) vs. 0/23 (0%), P=0.0001] than that in vMS. Clinicodemographic data might aid in recognizing different subtypes of TmMS and warrant consideration of unconventional therapies because outcomes may be poor in the vInf of TmMS.

Comparison of Translocator Protein Expression Between Tumefactive Multiple Sclerosis and Glioblastoma.

This figure presents a comparison of molecular imaging of the translocator protein (TSPO) and contrast-enhanced MRI in 2 patients with tumefactive multiple sclerosis and glioblastoma, respectively. In the case of the tumefactive multiple sclerosis patient, TSPO uptake is primarily located centrally, while in the glioblastoma patient, TSPO uptake is predominantly situated peripherally to the central necrotic area. These findings suggest that TSPO imaging could be a noninvasive imaging technique for distinguishing between these 2 diagnoses.

TUMEFACTIVE MULTIPLE SCLEROSIS: A DIAGNOSTIC ENIGMA. A CASE REPORT

Purpose: To present a clinical case of tumefactive multiple sclerosis (TMS), which is an inflammatory demyelinating disease of the central nervous system considered to be a rare form of multiple sclerosis (MS). It belongs to the group of borderline forms of MS – a collective term used to define a spectrum of demyelination-associated neurological conditions that share similar clinical, neuroimaging and histopathological features but vary widely in severity, clinical course and outcome. Materials/Methods: We describe the case of a 31-year-old female who was admitted to the Neurology clinic of UMHAT “Dr Georgi Stranski” in Pleven, Bulgaria, with a rapid onset of neurological deficit including right-sided hemiparesis, dysarthria, imbalance, cognitive impairment and urinary incontinence. MRI of the brain showed several tumor-like concentric lesions of demyelination surrounded by moderate brain edema, consistent with the radiological criteria for the demyelinating disease. Results: High-dosage corticosteroids were applied intravenously for this patient as acute therapy. A progressive improvement in the patient was achieved after the extended pulse corticosteroid therapy in combination with physiotherapy. Glatiramer acetate as a disease-modifying treatment was initiated within three months and had substantial efficacy. Conclusions: The diagnosis of TMS is always difficult and requires not only complex clinical and neuroimaging investigations but also an extensive follow-up of the patient. It is believed that TMS usually has a progressive course and an unfavorable outcome, but a relapsing-remitting course of TMS, albeit rare, is also possible. Our case report confirms that such benign variants of TMS exist. We believe that highlighting such complex clinical cases will contribute to a better understanding of the mystery of MS.

Cyclophosphamide for severe acute forms of central nervous system inflammatory disorders

Cyclophosphamide (CYC) may be an effective treatment in patients who fail first line therapy for severe central nervous system (CNS) inflammatory disorders including CNS vasculitis, neuromyelitis optica, autoimmune encephalitis, tumefactive and aggressive multiple sclerosis (MS). We performed a retrospective analysis of 46 patients treated with CYC after failing first line therapy for severe CNS inflammatory conditions. Primary outcomes included modified Rankin Scale (mRS) for patients classified into a non-MS group, Expanded Disability Status Score (EDSS) for MS patients, and Targeted Neurological Deficit score (TND) for all patients. Secondary outcome included neuroimaging studies following CYC treatment. By the second follow up period (average of 7 months) mRS in the non-MS group improved from 3.7 to 2.2 and EDSS in the MS group improved from 5.6 to 3.8. Average TND score at 7 months was 2.8 (mild-marked improvement). At first follow up (average 5.6 months), 76.2% (32/42) patients had either stable or improving imaging, and 83.3% (30/36) patients had stable or improving imaging at second follow up (average 13.6 months). Adverse events were reported by 31.9% of patients with most common being nausea and vomiting, headache, alopecia, and hyponatremia. Treatment with CYC can result in disease stabilization of severe CNS inflammatory diseases and is generally well tolerated.

Methionine-PET to differentiate between brain lesions appearing similar on conventional CT/MRI scans.

11 C-Methionine (MET)-PET is a useful tool in neuro-oncology. This study aimed to examine whether a combination of diagnostic variables associated with MET uptake could help distinguish between brain lesions that are often difficult to discriminate in conventional CT and MRI. MET-PET was assessed in 129 patients with glioblastoma multiforme, primary central nervous lymphoma, metastatic brain tumor, tumefactive multiple sclerosis, or radiation necrosis. The accuracy of the differential diagnosis was analyzed using five diagnostic characteristics in combination: higher maximum standardized uptake value (SUV) of MET in the lesion/the mean normal cortical SUV of MET ratio, overextension beyond gadolinium, peripheral pattern indicating abundant MET accumulation in the peripheral region, central pattern denoting abundant MET accumulation in the central region, and dynamic-up suggesting increased MET accumulation during dynamic study. The analysis was conducted on sets of two of the five brain lesions. Significant differences in the five diagnostic traits were observed among the five brain lesions, and differential diagnosis could be achieved by combining these diagnostic features. The area under the curve between each set of two of the five brain lesions using MET-PET features ranged from .85 to 1.0. According to the findings, combining the five diagnostic criteria could help with the differential diagnosis of the five brain lesions. MET-PET is an auxiliary diagnostic technique that could help in distinguishing these five brain lesions.

Spinal cord and brain corticospinal tract lesions are associated with motor progression in tumefactive multiple sclerosis

Spinal cord lesions have been associated with progressive disease in individuals with typical relapsing remitting MS (RRMS). In the current study, we aimed to determine if progressive disease is associated with spinal cord lesions in those with tumefactive multiple sclerosis (MS). Retrospective chart review of individuals presenting to Mayo Clinic with tumefactive MS with spinal cord MRIs available (n=159). Clinical data were extracted by chart review. Brain and spinal cord MRIs were reviewed to characterize the tumefactive demyelinating lesion(s) and assess the burden of spinal cord disease. A total of 69 (43%) had spinal cord lesions. Progressive demyelinating disease was documented in 13 (8%); the majority (11/13) with secondary progressive disease. The method of progression was myelopathic in 8/13 (62%), cognitive in 3/13 (23%), motor from a supratentorial lesion in 2/13 (16%). EDSS at last follow-up was higher in those with progression than those without (median 6.0 (2.0-10.0) vs. 2.5 (0-10.0), p=< 0.001). Progressive demyelinating disease occurred in a minority. Patients with progression typically experienced progressive motor impairment, and this occurred exclusively in individuals with lesions in the corticospinal tracts of the brain and/or the spinal cord.

Tumefactive multiple sclerosis – a diagnostic and therapeutic challenge

Tumefactive multiple sclerosis with the presence of tumefactive demyelinating lesions (TDL) is an infrequent manifestation of multiple sclerosis. It poses a diagnostic challenge, especially in attempts to differentiate it from a central nervous system neoplasm or other demyelinating disorders, such as neuromyelitis optica spectrum disorder (NMOSD). The article reports a case of a 40-year-old female during chronic steroid therapy administered due to an episode of idiopathic transverse myelitis. The patient developed tumour-like brain lesions in the left hemispheric parietal-occipital region. The diagnostic process was hindered by extended steroid treatment and a lack of patient compliance. This case is an example of insufficient knowledge about rare forms of multiple sclerosis and the need for a holistic approach involving a through analysis of medical history and previous medical records.

12 - Tumefactive multiple sclerosis: a complex experience with a great mimicker

12 - Tumefactive multiple sclerosis: a complex experience with a great mimicker

Brain and Spinal Cord MRI Findings in Thai Multiple Sclerosis Patients

Previous studies have demonstrated different MRI characteristics in Asian and Western patients with multiple sclerosis (MS). However, the number of studies performed on Thai patients is still limited. Furthermore, these studies were conducted before the revision of the McDonald criteria in 2017. A retrospective descriptive study was performed on Thai patients diagnosed with MS, according to the McDonald criteria (2017), in a tertiary care hospital in Thailand. Thirty-two patients were included (twenty-seven female and five male patients). The mean age was 37.8 years. Most (28 patients) had relapsing remitting MS. Brain MRIs were available for all 32 patients, all of which showed abnormalities. The most common locations were the periventricular regions (78.1%), juxtacortical regions (75%) and deep white matter (62.5%). Dawson's fingers were identified in 20 patients (62.5%). Tumefactive MS was noted in two patients. Gadolinium-enhancing brain lesions were noted in nine patients (28.1%). Optic nerve lesions were found in seven patients. Six of the seven patients showed short segmental lesions with predominant posterior-half involvement. Spinal MRIs were available for 26 patients, with abnormalities detected in 23. Most (11 patients) had lesions both in the cervical and in the thoracic spinal cord. In total, 22 patients (95.7%) showed lesions at the periphery, most commonly at the lateral column. Fifteen patients showed lesions shorter than three vertebral segments (65.2%). Enhancing spinal lesions were noted in 14 patients. Dissemination in space was fulfilled in 31 patients (96.9%). Some of the MRI findings in our study were similar to those of previous studies in Thailand and Asia, emphasizing the difference between Asian and Western MS.

Specific myeloid signatures in peripheral blood differentiate active and rare clinical phenotypes of multiple sclerosis.

Current understanding of Multiple Sclerosis (MS) pathophysiology implicates perturbations in adaptive cellular immune responses, predominantly T cells, in Relapsing-Remitting forms (RRMS). Nevertheless, from a clinical perspective MS is a heterogeneous disease reflecting the heterogeneity of involved biological systems. This complexity requires advanced analysis tools at the single-cell level to discover biomarkers for better patient-group stratification. We designed a novel 44-parameter mass cytometry panel to interrogate predominantly the role of effector and regulatory subpopulations of peripheral blood myeloid subsets along with B and T-cells (excluding granulocytes) in MS, assessing three different patient cohorts: RRMS, PPMS (Primary Progressive) and Tumefactive MS patients (TMS) (n=10, 8, 14 respectively). We further subgrouped our cohort into inactive or active disease stages to capture the early underlying events in disease pathophysiology. Peripheral blood analysis showed that TMS cases belonged to the spectrum of RRMS, whereas PPMS cases displayed different features. In particular, TMS patients during a relapse stage were characterized by a specific subset of CD11c+CD14+ CD33+, CD192+, CD172+-myeloid cells with an alternative phenotype of monocyte-derived macrophages (high arginase-1, CD38, HLA-DR-low and endogenous TNF-a production). Moreover, TMS patients in relapse displayed a selective CD4 T-cell lymphopenia of cells with a Th2-like polarised phenotype. PPMS patients did not display substantial differences from healthy controls, apart from a trend toward higher expansion of NK cell subsets. Importantly, we found that myeloid cell populations are reshaped under effective disease-modifying therapy predominantly with glatiramer acetate and to a lesser extent with anti-CD20, suggesting that the identified cell signature represents a specific therapeutic target in TMS. The expanded myeloid signature in TMS patients was also confirmed by flow cytometry. Serum neurofilament light-chain levels confirmed the correlation of this myeloid cell signature with indices of axonal injury. More in-depth analysis of myeloid subsets revealed an increase of a subset of highly cytolytic and terminally differentiated NK cells in PPMS patients with leptomeningeal enhancement (active-PPMS), compared to those without (inactive-PPMS). We have identified previously uncharacterized subsets of circulating myeloid cells and shown them to correlate with distinct disease forms of MS as well as with specific disease states (relapse/remission).

Tumefactive Demyelination in MOG Ab-Associated Disease, Multiple Sclerosis, and AQP-4-IgG-Positive Neuromyelitis Optica Spectrum Disorder.

Studies on tumefactive brain lesions in myelin oligodendrocyte glycoprotein-immunoglobulin G (IgG)-associated disease (MOGAD) are lacking. We sought to characterize the frequency clinical, laboratory, and MRI features of these lesions in MOGAD and compare them with those in multiple sclerosis (MS) and aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD). We retrospectively searched 194 patients with MOGAD and 359 patients with AQP4+NMOSD with clinical/MRI details available from the Mayo Clinic databases and included those with ≥1 tumefactive brain lesion (maximum transverse diameter ≥2 cm) on MRI. Patients with tumefactive MS were identified using the Mayo Clinic medical record linkage system. Binary multivariable stepwise logistic regression identified independent predictors of MOGAD diagnosis; Cox proportional regression models were used to assess the risk of relapsing disease and gait aid in patients with tumefactive MOGAD vs those with nontumefactive MOGAD. We included 108 patients with tumefactive demyelination (MOGAD = 43; AQP4+NMOSD = 16; and MS = 49). Tumefactive lesions were more frequent among those with MOGAD (43/194 [22%]) than among those with AQP4+NMOSD (16/359 [5%], p < 0.001). Risk of relapse and need for gait aid were similar in tumefactive and nontumefactive MOGAD. Clinical features more frequent in MOGAD than in MS included headache (18/43 [42%] vs 10/49 [20%]; p = 0.03) and somnolence (12/43 [28%] vs 2/49 [4%]; p = 0.003), the latter also more frequent than in AQP4+NMOSD (0/16 [0%]; p = 0.02). The presence of peripheral T2-hypointense rim, T1-hypointensity, diffusion restriction (particularly an arc pattern), ring enhancement, and Baló-like or cystic appearance favored MS over MOGAD (p ≤ 0.001). MRI features were broadly similar in MOGAD and AQP4+NMOSD, except for more frequent diffusion restriction in AQP4+NMOSD (10/15 [67%]) than in MOGAD (11/42 [26%], p = 0.005). CSF analysis revealed less frequent positive oligoclonal bands in MOGAD (2/37 [5%]) than in MS (30/43 [70%], p < 0.001) and higher median white cell count in MOGAD than in MS (33 vs 6 cells/μL, p < 0.001). At baseline, independent predictors of MOGAD diagnosis were the presence of somnolence/headache, absence of T2-hypointense rim, lack of T1-hypointensity, and no diffusion restriction (Nagelkerke R 2 = 0.67). Tumefactive lesion resolution was more common in MOGAD than in MS or AQP4+NMOSD and improved model performance. Tumefactive lesions are frequent in MOGAD but not associated with a worse prognosis. The clinical, MRI, and CSF attributes of tumefactive MOGAD differ from those of tumefactive MS and are more similar to those of tumefactive AQP4+NMOSD with the exception of lesion resolution, which favors MOGAD.