A Review of Clinical and Imaging Findings in Tumefactive Demyelination

Pearls & Oy-sters: Tumour-Like Mass Lesion Secondary to Primary CNS Vasculitis

Primary CNS vasculitis (PCNSV) is uncommonly considered in the differential diagnosis of tumor-like lesions. This case report of tumefactive PCNSV highlights imaging features that should increase clinical suspicion for CNS vasculitis, potentially lending to earlier diagnosis and treatment. A 62-year-old man presented with a 1-month history of focal motor seizures and cortical sensory loss localizing to the right frontoparietal lobe. Noncontrast head CT was suggestive of glioma, resulting in intravenous dexamethasone administration and admission to neurosurgery. MRI appearance was atypical for glioma, with relative preservation of regional anatomy, intralesional microhemorrhage, and patchy peripheral enhancement. Despite normal CT angiogram, CSF, and serum inflammatory markers, brain biopsy was suggestive of lymphocytic vasculitis. Extensive workup for secondary causes was negative, and he was diagnosed with tumefactive PCNSV. Treatment with corticosteroids and cyclophosphamide resulted in sustained clinical and radiologic improvement. Tumefactive PCNSV is an angiogram-negative small-vessel vasculitis that has a lymphocytic histologic pattern. Tumefactive PCNSV constitutes over 10% of PCNSV cases and can be recognized by the presence of intralesional microhemorrhages, absence of diffusion restriction, and a patchy or nodular enhancement pattern. The most important mimicker is CNS lymphoma, which has a similar imaging and histologic pattern. If individuals with tumefactive PCNSV do not have a sustained immunotherapy response, repeat biopsy should be promptly performed.

Abbreviated MRI in the evaluation of dizziness: report turnaround times and impact on length of stay compared to CT, CTA, and conventional MRI

PURPOSE

Neuroimaging is often used in the emergency department (ED) to evaluate for posterior circulation strokes in patients with dizziness, commonly with CT/CTA due to speed and availability. Although MRI offers more sensitive evaluation, it is less commonly used, in part due to slower turnaround times. We assess the potential for abbreviated MRI to improve reporting times and impact on length of stay (LOS) compared to conventional MRI (as well as CT/CTA) in the evaluation of acute dizziness.

MATERIALS AND METHODS

We performed a retrospective analysis of length of stay via LASSO regression for patients presenting to the ED with dizziness and discharged directly from the ED over 4 years (1/1/2018-12/31/2021), controlling for numerous patient-level and logistical factors. We additionally assessed turnaround time between order and final report for various imaging modalities.

RESULTS

14,204 patients were included in our analysis. Turnaround time for abbreviated MRI was significantly lower than for conventional MRI (4.40 h vs. 6.14 h, p < 0.001) with decreased impact on LOS (0.58 h vs. 2.02 h). Abbreviated MRI studies had longer turnaround time (4.40 h vs. 1.41 h, p < 0.001) and was associated with greater impact on ED LOS than non-contrast CT head (0.58 h vs. 0.00 h), however there was no significant difference in turnaround time compared to CTA head and neck (4.40 h vs. 3.86 h, p = 0.06) with similar effect on LOS (0.58 h vs. 0.53 h). Ordering both CTA and conventional MRI was associated with a greater-than-linear increase in LOS (additional 0.37 h); the same trend was not seen combining CTA and abbreviated MRI (additional 0.00 h).

CONCLUSIONS

In the acute settings where MRI is available, abbreviated MRI protocols may improve turnaround times and LOS compared to conventional MRI protocols. Since recent guidelines recommend MRI over CT in the evaluation of dizziness, implementation of abbreviated MRI protocols has the potential to facilitate rapid access to preferred imaging, while minimizing impact on ED workflows.

Tumefactive Multiple Sclerosis: The Lethal Chameleon

Tumefactive multiple sclerosis (TMS) is a rare variant of multiple sclerosis that presents with a large demyelinating lesion in the central nervous system, accompanied by peripheral ring-like enhancement, perilesional oedema and mass effect. We report a case of a 59-year-old woman who was admitted to the hospital with a four-day history of somnolence, muscle weakness in her left extremities and ultimately, loss of consciousness. Over the following 48 hours, the patient's condition worsened with progressive consciousness impairment. Although the results of the initial head computed tomography (CT) scan supported the diagnosis of a multifocal ischaemic stroke, toxoplasmosis was proposed as the most credible diagnostic hypothesis by brain magnetic resonance imaging (MRI). Due to the adverse clinical progression following the initiation of targeted therapy and inconclusive investigation, a brain biopsy was performed, which was indicative of active TMS in a subacute phase. The patient was started on plasmapheresis and natalizumab along with corticosteroids, with a very good response. In conclusion, we report a biopsy-proven TMS diagnosis in a patient that clinically mimicked an acute stroke and was radiographically confounded with intracranial toxoplasmosis. It highlights that TMS is an uncommon neurological demyelinating disease that is often misdiagnosed. It also emphasises the importance of establishing an accurate differential diagnosis to promptly initiate aggressive immunosuppressive treatment, which may result in a more favourable prognosis.

LEARNING POINTS

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.

Relapsing tumefactive demyelination lesions: A unique, distinct inflammatory brain pathology

We report the case of a patient suffering from biopsy-proven relapsing tumefactive demyelinating lesions (TDLs) of the central nervous system who had five relapses in 16 years. No signs/symptoms suggestive of alternative pathologies emerged during the follow-up. A limited benefit was observed with intravenous (IV) high-dose steroids, while both plasma exchange and IV immunoglobulin G (IgG) administration were ineffective. A long-lasting (9 years) but transient clinical stabilization was obtained with cyclophosphamide. Our case supports the view that recurrent TDL is a relapsing brain inflammation not belonging to multiple sclerosis (MS) or myelin oligodendrocyte glycoprotein (MOG)-/AQP4-associated disorders. TDL concept and clinical features should be revised.

Acute Hemorrhagic Leukoencephalitis in a Patient With Hepatitis B

Acute hemorrhagic leukoencephalitis (AHLE), also known as Weston-Hurst syndrome or Hurst disease, is a rare and rapidly progressive form of acute disseminated encephalomyelitis. It is characterized by severe inflammation, hemorrhage, and necrosis within the white matter of the brain. AHLE often follows an upper respiratory infection or other systemic illnesses, suggesting a potential post-infectious autoimmune mechanism. The disease is associated with a high mortality rate and significant disability among survivors. We present the case of a 46-year-old Indian woman with a history of chronic hepatitis B (HBV) who presented with an insidious onset of right-sided limb weakness and bi-frontal headaches. Initial brain MRIs showed features of tumefactive demyelination. Despite aggressive treatment with intravenous (IV) methylprednisolone, IV immunoglobulin, and anti-edema measures, the patient's condition rapidly deteriorated, leading to a diagnosis of AHLE following the emergence of hemorrhagic white matter lesions on repeat MRI. Remarkably, with continued treatment, the patient survived and showed gradual neurological improvement, although she remained significantly debilitated at the time of discharge. AHLE represents one of the most severe forms of demyelinating diseases, often resulting in rapid neurological decline and high mortality. This case highlights the potential link between chronic HBV infection with a high viral load and the onset of AHLE. The patient's recovery underscores the importance of early recognition and aggressive treatment in improving outcomes, even in conditions with traditionally poor prognosis. Clinicians should maintain a high index of suspicion for AHLE in patients with chronic viral infections presenting with neurological symptoms. Prompt and aggressive management can be life-saving, and ongoing research is needed to better understand the pathogenesis and optimal treatment strategies for this rare but devastating condition.

Cerebral Tumefactive Inflammatory Lesion Occurrence During Ixekizumab Treatment in a Patient With Active Psoriatic Arthritis

INTRODUCTION

Ixekizumab is an anti-interleukin-17A (IL-17A) humanized monoclonal antibody approved for the treatment of moderate-to-severe plaque psoriasis, active psoriatic arthritis, and ankylosing spondylitis. Central nervous system inflammatory manifestations are atypical during therapy with IL-17A inhibitors, with only one case of myelitis described to date.

CASE REPORT

A 72-year-old man with a medical history of active psoriatic arthritis was admitted to our department owing to the acute onset of left face numbness 1 month after the first ixekizumab administration. Magnetic resonance imaging of the brain displayed a large T2-hyperintense infratentorial lesion involving the root of the fifth and seventh left cranial nerves. A thorough laboratoristic and instrumental work-up did not show elements suggestive of extracerebral neoplasms or infections. Therefore, neuronavigation-assisted brain biopsy was performed, and histologic analysis of the lesion revealed the presence of wide aggregates of foamy histiocytes diffusely infiltrating the brain parenchyma, in the absence of malignant tissue or histologic elements suggestive of central nervous system infections or primary histiocytoses. Steroid treatment (dexamethasone 8 mg/daily) was then administered with subsequent clinical amelioration. One month after hospital discharge, a brain magnetic resonance imaging showed a nearly complete resolution of the lesion.

CONCLUSION

This is the first case of a cerebral inflammatory lesion occurring during treatment with ixekizumab. Although very rare, neurological complications may occur during anti-IL-17A therapies, thus leading to the need for careful monitoring of patients exposed to these drugs.

Emergent Management of Central Nervous System Demyelinating Disorders

OBJECTIVE

This article reviews the various conditions that can present with acute and severe central nervous system demyelination, the broad differential diagnosis of these conditions, the most appropriate diagnostic workup, and the acute treatment regimens to be administered to help achieve the best possible patient outcomes.

LATEST DEVELOPMENTS

The discovery of anti-aquaporin 4 (AQP4) antibodies and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in the past two decades has revolutionized our understanding of acute demyelinating disorders, their evaluation, and their management.

ESSENTIAL POINTS

Demyelinating disorders comprise a large category of neurologic disorders seen by practicing neurologists. In the majority of cases, patients with these conditions do not require care in an intensive care unit. However, certain disorders may cause severe demyelination that necessitates intensive care unit admission because of numerous simultaneous multifocal lesions, tumefactive lesions, or lesions in certain brain locations that lead to acute severe neurologic dysfunction. Intensive care may be necessary for the management and prevention of complications for patients who have severely altered mental status, rapidly progressive neurologic worsening, elevated intracranial pressure, severe cerebral edema, status epilepticus, or respiratory failure.

Prognostic factors of tumefactive demyelinating lesions and differential features for multiple sclerosis in etiology

BACKGROUND

Many different pathologies may underlie tumefactive demyelinating lesions. Identifying clinical and radiologic distinguishing features before pathologic examination is essential for diagnosis and treatment. In this study, we aimed to determine the clinical and radiologic features affecting the etiology and disease course of patients with tumefactive lesions (TDL).

MATERIALS AND METHODS

We included 35 clinicoradiologically or histologically diagnosed TDL patients in our center over 11 years. Patient records were retrospectively evaluated and recorded. Clinical features, cerebral neuroimaging, and histologic biopsy preparations, if any, were assessed by three independent neurologists, two neuroradiologists, and two pathologists at admission and follow-up, respectively.

RESULTS

The mean age of patients with TDL was 40.02±14.40 years. Symptom onset was 15 (1-365) days. The most common complaints at initial presentation were hemiparesis or hemiplegia, sensory complaints, and cognitive impairment (aphasia or apraxia). The lesions were most commonly localized in the frontal lobe (42.9 %). Mass effect was 17.1 %, edema 60 %, diffusion restriction 62.1 %, and contrast enhancement 71.9 % (mostly ring-shaped (68.8 %)) on MR images. Acute onset and OCB type-2 positivity were associated with MS diagnosis. On the other hand, CSF protein levels above 45 mg/dL were found to be related to non-MS etiologies. Only the predominance of aphasia or apraxia at onset was a risk factor for early high disability (EDSS>4; 3rd month). Subacute-chronic onset, being older than 40 years, or having brainstem symptoms at onset were independent risk factors for late high disability (2nd year).

CONCLUSION

Acute onset or OCB type 2 positivity is a clue for early diagnosis of MS, while elevated CSF protein is a clue for demyelinating diseases other than MS. Presentation with cognitive dysfunction at onset is an independent risk factor for early disability, while age above 40 years, subacute-chronic presentation and brainstem findings at presentation are independent risk factors for late disability.

Tumefactive Demyelinating Lesions: An Illustrative Pediatric Case With an Atypical Presentation and Literature Review

Tumefactive demyelinating lesions remain a rare entity and a source of diagnostic difficulty. Here, we report the case of a teenage girl who presented with a one-month history of progressive quadriparesis and symptoms of intracranial hypertension. Brain MRI showed multiple large subcortical white matter lesions with both open- and closed-rim enhancement on gadolinium injection. The patient subsequently underwent a brain biopsy which showed an inflammatory infiltrate and no signs of malignancy. She was treated with pulse intravenous methylprednisolone at a dose of 500mg per day for five days and had rapid improvement. Her symptoms fully resolved after three months. This case highlights the need for better recognition and diagnosis of tumefactive demyelination, potentially avoiding unnecessary invasive diagnostic procedures such as brain biopsies.

A Rare and Challenging Presentation of Acute Hemorrhagic Leukoencephalitis With Tumefactive Demyelinating Lesions in a 41-Year-Old Male

Acute hemorrhagic leukoencephalitis (AHLE) is a rare and severe inflammatory condition of the central nervous system (CNS), characterized by hemorrhagic lesions in the brain's white matter. Here, we present a case of AHLE with concurrent tumefactive demyelinating disease, highlighting the diagnostic and management challenges associated with this complex presentation. Tumefactive multiple sclerosis (MS) is a rare variant of MS characterized by large, space-occupying lesions in the CNS. Concurrently, hemorrhagic leukoencephalitis (HLE) represents a severe inflammatory disorder characterized by hemorrhagic lesions within the CNS white matter. The diagnosis of tumefactive MS with associated HLE posed significant diagnostic challenges due to overlapping clinical and radiological features. Management involved high-dose corticosteroid therapy and supportive care measures, with longitudinal follow-up to assess treatment response and prevent complications. The patient exhibited a favorable clinical response to treatment, with gradual improvement in symptoms and resolution of radiological abnormalities. The coexistence of tumefactive MS with HLE is exceptionally rare and presents diagnostic and therapeutic challenges. We report a 41-year-old male presenting with acute neurological symptoms, including severe headache, confusion, left-sided body weakness, slurred speech, and blurred vision. Neurological examination revealed dysarthric speech, right homonymous hemianopia, left upper motor neuron facial palsy, and motor deficits. MRI demonstrated multifocal areas of T2 hyperintensity with associated hemorrhage, suggestive of tumefactive MS with associated HLE. Diagnostic workup included neurological examination, MRI imaging, cerebrospinal fluid analysis, and serological testing. Management involved high-dose corticosteroid therapy and supportive care measures. The patient exhibited a favorable clinical response to treatment, with gradual improvement in symptoms and resolution of radiological abnormalities. Longitudinal follow-up confirmed sustained improvement. In conclusion, the coexistence of tumefactive MS with HLE poses diagnostic challenges due to overlapping features. This case underscores the importance of considering rare and atypical presentations of CNS demyelinating disease and the potential complications, including associated HLE. Comprehensive evaluation, multidisciplinary collaboration, and individualized management are essential for optimizing outcomes in patients with complex CNS inflammatory disorders.

Catastrophic tumefactive acute disseminated encephalomyelitis in patient with dengue virus: a case report

Tumefactive demyelinating lesions (TDL) are a rare occurrence among inflammatory demyelinating diseases of the central nervous system, distinguished by tumor-like lesions exceeding 2 cm in diameter. While various etiologies have been associated with TDL, only a limited number of case reports document the coexistence of acute disseminated encephalomyelitis (ADEM) and TDL. Here, we present the case of a female diagnosed with dengue fever two weeks prior, who subsequently developed left hemiparesis and encephalopathy. Both her brain magnetic resonance imaging (MRI) and clinical course align with the characteristics of tumefactive ADEM.

Tumefactive demyelinating lesions: a retrospective cohort study in Thailand

Tumefactive demyelinating lesions (TDL), characterized by large (≥ 2 cm) demyelinating lesions mimicking tumors, are a rare manifestation of the central nervous system inflammatory demyelinating diseases (CNS-IDD). Distinguishing TDL from other brain lesions can be challenging, often necessitating biopsy or advanced diagnostics. The natural history of TDL varies among races. This study aimed to assess demographics, clinical and radiological features, laboratory findings, management, and outcomes of Thai patients with TDL. We retrospectively reviewed records of twenty-six patients with TDL from the Multiple Sclerosis and Related Disorders registry from two tertiary medical centers. Among 1102 CNS-IDD patients, 26 (2.4%) had TDL. The median age at TDLs onset was 34.5 years (range 17-75); 69.2% were female. Over 70% manifested TDL as their initial CNS-IDD presentation. Common presenting symptoms included motor deficits, sensory disturbances, and cognitive problems. About two-fifths exhibited multiple lesions, most frequently in the frontoparietal region (46.2%). Half of the patients showed an incomplete ring on post-contrast T1-weighted imaging, with peripheral diffusion-weighted imaging restriction in twenty-one patients. T2-hypointense rims were present in thirteen (56.5%) patients. Brain biopsy was performed in 12 cases (46.1%). Serum aquaporin-4 immunoglobulin was positive in 16.7% of tested (4/24) cases. Serum myelin oligodendrocyte glycoprotein immunoglobulin was negative in all thirteen patients tested. Twenty patients (76.9%) received intravenous corticosteroids for TDL attacks. After the median follow-up period of 48 months (range 6-300), 23.1% experienced CNS-IDD relapses. Median Expanded Disability Status Scale at TDL diagnosis was 4.3 (range 0.0-9.5), and improved to 3.0 (range 0.0-10.0) at the last follow-up. This study suggested that TDL were rare among Thai CNS-IDD patients, frequently presenting as a monophasic condition with a favorable outcome.

Differential Diagnosis of Tumor-like Brain Lesions

Purpose of Review

Tumor-like brain lesions are rare and commonly suggest a neoplastic etiology. Failure to rapidly identify non-neoplastic causes can lead to increased morbidity and mortality. In this review, we describe 10 patients who presented with atypical, non-neoplastic tumor-like brain lesions in which brain biopsy was essential for a correct diagnosis and treatment.

Recent Findings

There has been increasing recognition of autoimmune conditions affecting the nervous system, and many of those diseases can cause tumor-like brain lesions. Currently available reports of non-neoplastic tumor-like brain lesions are scarce. Most case series focus on tumefactive demyelinating lesions, and a comprehensive review including other neuroimmunological conditions such as CNS vasculitis, neurosarcoidosis, histiocytic and infectious etiologies is lacking.

Summary

We review the literature on tumor-like brain lesions intending to increase the awareness and differential diagnosis of non-neoplastic brain tumor mimics. We advocate for earlier brain biopsies, which, in our case series, significantly changed diagnosis, management, and outcomes.

Comparison of Translocator Protein Expression Between Tumefactive Multiple Sclerosis and Glioblastoma

ABSTRACT

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.

Phenotyping variants of tumefactive demyelinating lesions according to clinical and radiological features-A case series

Background

Tumefactive demyelinating lesions (TDLs) are defined as lesions >2 cm on MRI of the brain. They are identified in a range of demyelinating diseases including massive demyelination due to Marburg's acute MS, Schilder's Disease, Balo's concentric sclerosis, and Tumefactive MS. Apart from the rare demyelinating variants which are often diagnosed histologically, there are no detailed data to phenotype TDLs.

Methods

We describe the clinical and radiological features of four similar patients with very large TDLs (>4 cm), that are not consistent with the rare demyelinating variants and may represent a distinct phenotype.

Results

All patients presented with hemiplegia and apraxia. The mean age at onset was 37 years with an equal sex distribution. All patients were diagnosed with Tumefactive demyelination based on MRI and CSF analysis, precluding the need for brain biopsy. All responded to potent immunotherapy (including high dose corticosteroids, plasma exchange, rituximab, and/or cyclophosphamide). The mean lag from diagnosis to treatment was 1 day. The median EDSS at presentation was six and recovery to a median EDSS of two occurred over 6 months.

Conclusion

We propose that Tumefactive lesions larger than 4 cm are termed "Giant demyelinating lesions" (GDLs) not only on the basis of size, but a rapid and fulminant demyelinating presentation leading to acute, severe neurological disability that is, nonetheless, responsive to immunotherapy. Further clinical studies are required to ratify this proposed phenotype, establish the immunological profile and best treatment for such patients.

The value of convolutional neural networks-based deep learning model in differential diagnosis of space-occupying brain diseases

Objectives

It is still a challenge to differentiate space-occupying brain lesions such as tumefactive demyelinating lesions (TDLs), tumefactive primary angiitis of the central nervous system (TPACNS), primary central nervous system lymphoma (PCNSL), and brain gliomas. Convolutional neural networks (CNNs) have been used to analyze complex medical data and have proven transformative for image-based applications. It can quickly acquire diseases' radiographic features and correct doctors' diagnostic bias to improve diagnostic efficiency and accuracy. The study aimed to assess the value of CNN-based deep learning model in the differential diagnosis of space-occupying brain diseases on MRI.

Methods

We retrospectively analyzed clinical and MRI data from 480 patients with TDLs (n = 116), TPACNS (n = 64), PCNSL (n = 150), and brain gliomas (n = 150). The patients were randomly assigned to training (n = 240), testing (n = 73), calibration (n = 96), and validation (n = 71) groups. And a CNN-implemented deep learning model guided by clinical experts was developed to identify the contrast-enhanced T1-weighted sequence lesions of these four diseases. We utilized accuracy, sensitivity, specificity, and area under the curve (AUC) to evaluate the performance of the CNN model. The model's performance was then compared to the neuroradiologists' diagnosis.

Results

The CNN model had a total accuracy of 87% which was higher than senior neuroradiologists (74%), and the AUC of TDLs, PCNSL, TPACNS and gliomas were 0.92, 0.92, 0.89 and 0.88, respectively.

Conclusion

The CNN model can accurately identify specific radiographic features of TDLs, TPACNS, PCNSL, and gliomas. It has the potential to be an effective auxiliary diagnostic tool in the clinic, assisting inexperienced clinicians in reducing diagnostic bias and improving diagnostic efficiency.

Central nervous system tumefactive demyelinating lesions: Risk factors of relapse and follow-up observations

Objective

To track the clinical outcomes in patients who initially presented with tumefactive demyelinating lesions (TDLs), we summarized the clinical characteristics of various etiologies, and identified possible relapse risk factors for TDLs.

Methods

Between 2001 and 2021, 116 patients initially presented with TDLs in our hospital were retrospectively evaluated. Patients were followed for relapse and clinical outcomes, and grouped according to various etiologies. Demographic information, clinical data, imaging data, and laboratory results of patients were obtained and analyzed. The risk factors of relapse were analyzed by the Log-Rank test and the Cox proportional hazard model in multivariate analysis.

Result

During a median follow-up period of 72 months, 33 patients were diagnosed with multiple sclerosis (MS), 6 patients with Balo, 6 patients with neuromyelitis optica spectrum disorders (NMOSD), 10 patients with myelin oligodendrocyte glycoprotein antibody-associated demyelination (MOGAD), 1 patient with acute disseminated encephalomyelitis (ADEM), and the remaining 60 patients still have no clear etiology. These individuals with an unknown etiology were categorized independently and placed to the other etiology group. In the other etiology group, 13 patients had recurrent demyelinating phases, while 47 patients did not suffer any more clinical events. Approximately 46.6% of TDLs had relapses which were associated with multiple functional system involvement, first-phase Expanded Disability Status Scale score, lesions morphology, number of lesions, and lesions location (P<0.05). And diffuse infiltrative lesions (P=0.003, HR=6.045, 95%CI:1.860-19.652), multiple lesions (P=0.001, HR=3.262, 95%CI:1.654-6.435) and infratentorial involvement (P=0.006, HR=2.289, 95%CI:1.064-3.853) may be independent risk factors for recurrence. Relapse free survival was assessed to be 36 months.

Conclusions

In clinical practice, around 46.6% of TDLs relapsed, with the MS group showing the highest recurrence rate, and lesions location, diffuse infiltrative lesions, and multiple lesions might be independent risk factors for relapse. Nevertheless, despite extensive diagnostic work and long-term follow-up, the etiology of TDLs in some patients was still unclear. And these patients tend to have monophase course and a low rate of relapse.

Neuroimaging and clinicopathological differences between tumefactive demyelinating lesions and sentinel lesions of primary central nervous system lymphoma

Objective

It is still a challenge to distinguish sentinel lesions of primary central nervous system lymphoma (PCNSL) from atypical tumefactive demyelinating lesions (TDLs) in clinical practice. We aimed to investigate potential differences of clinical features, neuroimaging findings and pathological characteristics between PCNSL and TDLs, improving early accurate diagnosis.

Methods

It was a retrospective study involving 116 patients with TDLs and 150 patients with PCNSLs. All cases were pathologically confirmed. Clinical features, neuroimaging findings and pathological characteristics between two groups were analyzed.

Results

The onset age was 37 ± 14 years in TDLs and 58 ± 13 years in PCNSL(p=0.000). Main onset symptom was headache in TDLs, while cognitive impairment was frequently noted in PCNSL. CT brain scan image showed hypodense lesions in most cases of TDL (110/116, 94.8%), while approximately 80% patients (120/150) with PCNSL had hyperdense lesions. Furthermore, we found that the presence of Creutzfeldt-Peters cells (might be misdiagnosed as tumor cells) may serve as an important feature in TDLs.

Conclusions

Onset age of patients with TDLs was younger than PCNSL. Neuroimaging features on brain CT scan might provide clues to make a differential diagnosis. Pathological features of PCNSL with sentinel lesions or following steroids therapy might mimic TDLs. Dynamic neuroimaging pathological and follow-up information were essential for an accurate diagnosis.

The landscape of brain tumor mimics in neuro-oncology practice

BACKGROUND AND OBJECTIVE

Differentiating neoplastic and non-neoplastic brain lesions is essential to make management recommendations and convey prognosis, but the distinction between brain tumors and their mimics in practice may prove challenging. The aim of this study is to provide the incidence of brain tumor mimics in the neuro-oncology setting and describe this patient subset.

METHODS

Retrospective study of adult patients referred to the Division of Neuro-oncology for a presumed diagnosis of brain tumor from January 1, 2005 through December 31, 2017, who later satisfied the diagnosis of a non-neoplastic entity based on neuroimaging, clinical course, and/or histopathology evaluation. We classified tumor mimic entities according to clinical, radiologic, and laboratory characteristics that correlated with the diagnosis.

RESULTS

The incidence of brain tumor mimics was 3.4% (132/3897). The etiologies of the non-neoplastic entities were vascular (35%), inflammatory non-demyelinating (26%), demyelinating (15%), cysts (10%), infectious (9%), and miscellaneous (5%). In our study, 38% of patients underwent biopsy to determine diagnosis, but in 26%, the biopsy was inconclusive.

DISCUSSION

Brain tumor mimics represent a small but important subset of the neuro-oncology referrals. Vascular, inflammatory, and demyelinating etiologies represent two-thirds of cases. Recognizing the clinical, radiologic and laboratory characteristics of such entities may improve resource utilization and prevent unnecessary as well as potentially harmful diagnostic and therapeutic interventions.

Immunopathology of Tumefactive Demyelinating Lesions-From Idiopathic to Drug-Related Cases

Tumefactive demyelinating lesions (TDL) represent a diagnostic dilemma for clinicians, and in rare atypical cases a collaboration of a neuroradiologist, a neurologist, and a neuropathologist is warranted for accurate diagnosis. Recent advances in neuropathology have shown that TDL represent an umbrella under which many different diagnostic entities can be responsible. TDL can emerge not only as part of the spectrum of classic multiple sclerosis (MS) but also can represent an idiopathic monophasic disease, a relapsing disease with recurrent TDL, or could be part of the myelin oligodendrocyte glycoprotein (MOG)- and aquaporin-4 (AQP4)-associated disease. TDL can appear during the MS disease course, and increasingly cases arise showing an association with specific drug interventions. Although TDL share common features with classic MS lesions, they display some unique features, such as extensive and widespread demyelination, massive and intense parenchymal infiltration by macrophages along with lymphocytes (mainly T but also B cells), dystrophic changes in astrocytes, and the presence of Creutzfeldt cells. This article reviews the existent literature regarding the neuropathological findings of tumefactive demyelination in various disease processes to better facilitate the identification of disease signatures. Recent developments in immunopathology of central nervous system disease suggest that specific pathological immune features (type of demyelination, infiltrating cell type distribution, specific astrocyte pathology and complement deposition) can differentiate tumefactive lesions arising as part of MS, MOG-associated disease, and AQP4 antibody-positive neuromyelitis optica spectrum disorder. Lessons from immunopathology will help us not only stratify these lesions in disease entities but also to better organize treatment strategies. Improved advances in tissue biomarkers should pave the way for prompt and accurate diagnosis of TDL leading to better outcomes for patients.