MRI findings of primary CNS lymphoma in 26 immunocompetent patients

Primary central nervous system lymphoma: Imaging features and differential diagnosis

Primary central nervous system lymphoma (PCNSL) represents 5% of malignant primary brain tumors. The clinical presentation typically includes focal neurological symptoms, increased intracranial pressure, seizures, and psychiatric symptoms. Although histological examination remains the gold standard for diagnostic confirmation, non-invasive imaging plays a crucial role for the diagnosis. In immunocompetent individuals, PCNSL usually appears as a single, well-defined, supratentorial lesion with a predilection for periventricular areas, iso- or hypointense on T1- and T2-weighted magnetic resonance imaging, with restricted diffusion, slightly increased perfusion, and homogenous gadolinium-enhancement. Differential diagnoses include high-grade glioma and pseudotumoral demyelinating disease. In immunocompromised patients, PCNSL may present as multiple lesions, with a higher likelihood of hemorrhage and necrosis and less restricted diffusion than immunocompetent individuals. Differential diagnoses include neurotoxoplasmosis, progressive multifocal leukoencephalopathy, and cerebral abscess. Atypical forms of lymphoma are characterized by extra-axial lymphoma, lymphomatosis cerebri, and intravascular lymphoma. Extra-axial lymphoma presents as single or multiple extra-axial dural lesions with diffuse leptomeningeal contrast-enhancement. Lymphomatosis cerebri appears as an infiltrative and symmetric lesion, primarily affecting deep white matter and basal ganglia, appearing hyperintense on T2-weighted imaging, without significant contrast-enhancement or perfusion changes. Intravascular lymphoma presents as multiple rounded or oval-shaped "infarct-like" lesions, located cortically or subcortically. This study aims to highlight the imaging characteristics of PCNSL, focusing on magnetic resonance imaging and its differential diagnosis.

Differentiating between Lymphoma and Metastasis Presenting as Solid Cerebellar Mass Lacking Necrosis

Objectives: This study aimed to identify radiologic features that differentiate lymphoma from metastasis manifesting as a solid enhancing mass lacking necrosis in the cerebellum. Methods: Pathologically confirmed 24 primary central nervous system lymphoma (PCNSL) and 32 metastasis patients with solid enhancing cerebellar masses without necrotic or hemorrhagic components were retrospectively analyzed. We evaluated the imaging characteristics using contrast-enhanced magnetic resonance imaging (MRI). The serrate sign was defined as a tumor spreading along white matter with branch-like enhancement or outward spikes. Results: The serrate sign was exclusively identified in the PCNSL group, showing a significant difference compared to the metastasis group (75.0% vs. 0%, p < 0.001). Homogeneous enhancement occurred more frequently in PCNSL than in metastasis (91.7% vs. 21.9%, p < 0.001). Conversely, bulging contour (62.5% vs. 4.2%, p < 0.001) and surface involvement (71.9% vs. 29.2%, p = 0.003) were more prevalent in metastasis than PCNSL. For predicting PCNSL, the serrate sign demonstrated 75.0% sensitivity, 100% specificity, 100% positive predictive value, 84.2% negative predictive value, and 89.3% accuracy. Conclusions: This study found that the serrate sign and homogeneous enhancement are reliable MRI features for differentiating cerebellar PCNSL from metastasis, whereas a bulging contour and surface involvement suggest metastasis. The serrate sign demonstrated diagnostic significance in differentiating PCNSL from metastasis.

Rethinking the role of surgical resection in the management of primary pituitary lymphoma

BACKGROUND

Primary pituitary lymphoma (PPL) is a rare finding in immunocompetent patients, with only 54 patients reported to date (including ours). It presents most often with headache and hypopituitarism, with MRI findings comparable to more common pituitary tumours, making the diagnosis challenging. There is no consensus on the ideal management for these lesions with the role of surgical resection not clearly established.

CASE REPORT

We present here a 49-year-old female who presented with acute vision loss and was found to have PPL of diffuse large B-cell lymphoma, non-germinal centre type. The radiologic findings were distinct from prior cases with haemorrhagic components and perilesional edoema in the bilobed sellar mass. Surgical resection was halted when a diagnosis of lymphoma was suspected. This decision was based on the guidelines for the treatment of primary CNS lymphoma (PCNSL) and the lack of evidence to support surgical resection of PPL specifically. Our patient lacked mutations commonly associated with a poor prognosis in DLBCL, such as TP53 and BCL6. She remains in remission with normal vision nearly two years after treatment with minimal resection, MR-CHOP, and consolidation radiotherapy.

CONCLUSION

We highlight here the clinical and diagnostic features of PPL to guide clinicians to early recognition and diagnosis. Surgical resection should be limited to what is necessary to obtain a diagnosis and critical decompression; otherwise, these lesions respond excellently to steroids and typical chemoradiation regimens.

Primary central nervous system lymphomas in immunocompromised patients require specific response criteria

PURPOSE

Immunosuppression is a well-established risk factor for primary central nervous system lymphomas (PCNSLs), which present in this context distinct radiological characteristics. Our aim was to describe the radiological evolution of treated PCNSL in immunocompromised patients and suggest adapted MRI response criteria.

METHODS

We conducted a multicenter retrospective study of patients from the French LOC, K-Virogref and CANCERVIH network databases and enrolled adult immunocompromised patients with newly diagnosed PCNSL.

RESULTS

We evaluated the baseline, intermediate, end-of-treatment and follow-up MRI data of 31 patients (9 living with HIV, 16 with solid organ transplantation and 6 with an autoimmune disease under chronic immunosuppressive therapy). At baseline, 23/30 (77%) patients had necrotic lesions with ring enhancement and 28% of the lesions were hemorrhagic. At the end of the first-line treatment, 12/28 (43%) patients could not be classified according to the IPCG criteria. Thirteen of 28 (46%) patients still harbored contrast enhancement, and 11/28 (39%) patients had persistent large necrotic lesions with a median diameter of 15 mm. These aspects were not associated with a pejorative outcome and progressively diminished during follow-up. Six patients relapsed; however, we failed to identify any neuroimaging risk factors on the end-of-treatment MRI.

CONCLUSION

In immunocompromised patients, PCNSLs often harbor alarming features on end-of-treatment MRI, with persistent contrast-enhanced lesions frequently observed. However, these aspects seemed to be related to the necrotic and hemorrhagic nature of the lesions and were not predictive of a pejorative outcome. Specific response criteria for this population are thereby proposed.

Predictors for the Differentiation between Glioblastoma, Primary Central Nervous System Lymphoma, and Metastasis in Patients with a Solitary Enhancing Intracranial Mass

Introduction  Differentiation between glioblastoma (GBM), primary central nervous system lymphoma (PCNSL), and metastasis is important in decision-making before surgery. However, these malignant brain tumors have overlapping features. This study aimed to identify predictors differentiating between GBM, PCNSL, and metastasis. Materials and Methods  Patients with a solitary intracranial enhancing tumor and a histopathological diagnosis of GBM, PCNSL, or metastasis were investigated. All patients with intracranial lymphoma had PCNSL without extracranial involvement. Demographic, clinical, and radiographic data were analyzed to determine their associations with the tumor types. Results  The predictors associated with GBM were functional impairment ( p  = 0.001), large tumor size ( p  < 0.001), irregular tumor margin ( p  < 0.001), heterogeneous contrast enhancement ( p  < 0.001), central necrosis ( p  < 0.001), intratumoral hemorrhage ( p  = 0.018), abnormal flow void ( p  < 0.001), and hypodensity component on noncontrast cranial computed tomography (CT) scan ( p  < 0.001). The predictors associated with PCNSL comprised functional impairment ( p  = 0.005), deep-seated tumor location ( p  = 0.006), homogeneous contrast enhancement ( p  < 0.001), absence of cystic appearance ( p  = 0.008), presence of hypointensity component on precontrast cranial T1-weighted magnetic resonance imaging (MRI; p  = 0.027), and presence of isodensity component on noncontrast cranial CT ( p  < 0.008). Finally, the predictors for metastasis were an infratentorial ( p  < 0.001) or extra-axial tumor location ( p  = 0.035), smooth tumor margin ( p  < 0.001), and presence of isointensity component on cranial fluid-attenuated inversion recovery MRI ( p  = 0.047). Conclusion  These predictors may be used to differentiate between GBM, PCNSL, and metastasis, and they are useful in clinical management.

Differentiation of glioblastoma and primary central nervous system lymphomas using multiparametric diffusion and perfusion magnetic resonance imaging

The present study aimed to determine whether combining diffusion-weighted (DWI) and dynamic susceptibility contrast-enhanced perfusion-weighted (DSC-PWI) magnetic resonance imaging (MRI) could differentiate between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM). The present retrospective study evaluated 45 patients with histologically confirmed brain tumors, of which 18 had PCNSLs and 27 had GBMs. All patients underwent conventional, DWI, and DSC-PWI MRIs before the surgical removal of the lesion or stereotactic biopsy. The solid tumor component, peritumoral edema, and abnormal white matter were measured in three regions of interest to evaluate relative cerebral blood volume (rCBV), apparent diffusion coefficient (ADC) and DWI. In conventional MRI, there were significant differences in tumor numbers, tumor enhancement type, tumor necrosis, hemorrhage and open-ring sign between GBM and PCNSL. Solid tumor ADC and rCBV values (ADCt and rCBVt, respectively) and their ratios with abnormal white matter amounts were significantly higher in GBM cases than in PCNSL cases (P<0.05). The rCBV value for peritumoral edema (rCBVe) and its ratio with abnormal white matter amount (rCBVe/n) were significantly higher in GBM cases than in PCNSL cases (P<0.05). However, ADC values did not differ significantly for peritumoral edema. DWI values did not differ significantly. Combining rCBVt and rCBVe/n provided a perfect area under the receiver operating characteristic curve of 1.00, with 100% sensitivity and 100% specificity for distinguishing GBM from PCNSL. In the results of the present study, the major criterion in the decision-making process distinguishing PCNSL from GBM was the combined rCBVt and rCBVe/n parameter. A minor criterion was the ADCt value of the lesion.

[18F]FDG PET-MRI provides survival biomarkers in primary central nervous system lymphoma in the elderly: an ancillary study from the BLOCAGE trial of the LOC network

PURPOSE

Primary central nervous system lymphoma (PCNSL) incidence is rising among elderly patients, presenting challenges due to poor prognosis and treatment-related toxicity risks. This study explores the potential of combining [18F]fluorodeoxyglucose ([18F]FDG) PET scans and multimodal MRI for improving management in elderly patients with de novo PCNSL.

METHODS

Immunocompetent patients over 60 years with de novo PCNSL were prospectively enrolled in a multicentric study between January 2016 and April 2021. Patients underwent brain [18F]FDG PET-MRI before receiving high-dose methotrexate-based chemotherapy. Relationships between extracted PET (metabolic tumor volume (MTV), sum of MTV for up to five lesions (sumMTV), metabolic imaging lymphoma aggressiveness score (MILAS)) and MRI parameters (tumor contrast-enhancement size, cerebral blood volume (CBV), cerebral blood flow (CBF), apparent diffusion coefficient (ADC)) and treatment response and outcomes were analyzed.

RESULTS

Of 54 newly diagnosed diffuse large B-cell PCNSL patients, 52 had positive PET and MRI with highly [18F]FDG-avid and contrast-enhanced disease (SUVmax: 27.7 [22.8-36]). High [18F]FDG uptake and metabolic volume were significantly associated with low ADCmean values and high CBF at baseline. Among patients, 69% achieved an objective response at the end of induction therapy, while 17 were progressive. Higher cerebellar SUVmean and lower sumMTV at diagnosis were significant predictors of complete response: 6.4 [5.7-7.7] vs 5.4 [4.5-6.6] (p = 0.04) and 5.5 [2.1-13.3] vs 15.9 [4.2-19.5] (p = 0.01), respectively. Two-year overall survival (OS) was 71%, with a median progression-free survival (PFS) of 29.6 months and a median follow-up of 37 months. Larger tumor volumes on PET or enhanced T1-weighted MRI were significant predictors of poorer OS, while a high MILAS score at diagnosis was associated with early death (< 1 year).

CONCLUSION

Baseline cerebellar metabolism and sumMTV may predict response to end of chemotherapy in PCNSL. Tumor volume and MILAS at baseline are strong prognostic factors.

Primary central nervous system lymphoma: a practical guide for neurologists

Primary central nervous system lymphoma is rare, comprising 4% of intracranial neoplasms. Although haematologists or oncologists subsequently manage the condition, it is often neurologists who first make, or at least suspect, the diagnosis. This article reviews the disease, its clinical and radiological features and details the work-up needed to achieve a diagnosis (namely histological or cytological confirmation) and to prepare the patient for treatment. We note the importance of brain biopsy, the role of corticosteroids and the varied treatment options.

Imaging Recommendations for the Diagnosis, Staging, and Management of Adult Brain Tumors

Neuroimaging plays a pivotal role in the clinical practice of brain tumors aiding in the diagnosis, genotype prediction, preoperative planning, and prognostication. The brain tumors most commonly seen in adults are extra-axial lesions like meningioma, intra-axial lesions like gliomas and lesions of the pituitary gland. Clinical features may be localizing like partial seizures, weakness, and sensory disturbances or nonspecific like a headache. On clinical suspicion of a brain tumor, the primary investigative workup should focus on imaging. Other investigations like fundoscopy and electroencephalography may be performed depending on the clinical presentation. Obtaining a tissue sample after identifying a brain tumor on imaging is crucial for confirming the diagnosis and planning further treatment. Tissue sample may be obtained by techniques such as stereotactic biopsy or upfront surgery. The magnetic resonance (MR) imaging protocol needs to be standardized and includes conventional sequences like T1-weighted (T1W) imaging with and without contrast, T2w imaging, fluid-attenuated axial inversion recovery, diffusion-weighted imaging (DWI), susceptibility-weighted imaging, and advanced imaging sequences like MR perfusion and MR spectroscopy. Various tumor characteristics in each of these sequences can help us narrow down the differential diagnosis and also predict the grade of the tumor. Multidisciplinary co-ordination is needed for proper management and care of brain tumor patients. Treatment protocols need to be adapted and individualized for each patient depending on the age, general condition of the patient, histopathological characteristics, and genotype of the tumor. Treatment options include surgery, radiotherapy, and chemotherapy. Imaging also plays a vital role in post-treatment follow-up. Sequences like DWI, MR perfusion, and MR spectroscopy are useful to distinguish post-treatment effects like radiation necrosis and pseudoprogression from true recurrence. Radiological reporting of brain tumor images should follow a structured format to include all the elements that could have an impact on the treatment decisions in patients.

Coexistence of primary central nervous system lymphoma and primary breast lymphoma: Clinical presentation, imaging features, and treatment management

The presence of synchronous dual hematological diseases is an uncommon finding. We report an unusual case of coexistence of primary central nervous system lymphoma and primary breast lymphoma without systemic involvement in an immunocompetent patient. To our knowledge a similar case has not yet been reported in the literature. We especially focus on presenting the imaging features, the associated clinical findings and treatment management of each entity, with the aim of raising awareness on these two rare types of lymphomas and the possibility of their coexistence.

Primary CNS lymphoma in Immunocompetent patients: Appearances on Conventional and Advanced Imaging with Review of literature

Primary central nervous system lymphoma (PCNSL) constitutes about 3% of all primary brain tumors and nearly 1 to 3% of all Non Hodgkin Lymphomas. In the recent years the incidence of primary CNS lymphoma is increasing in immunocompetent patients. As PCNSL are chemosensitive as well as radiosensitive, its early and accurate diagnosis is imperative for optimal management. Contrast enhanced Magnetic Resonance Imaging (MRI) is the recommended imaging modality for PCNSL; however, contrast enhanced Computed Tomography (CE-CT) is done in cases where MRI is contraindicated. Advanced imaging techniques like DWI (diffusion weighted imaging), MRS (MR Spectroscopy), MR perfusion, DTI (Diffusion tensor imaging) are important in diagnosis and help in its differentiation from other tumors.

Primary CNS lymphoma of the corpus callosum: presentation and neurocognitive outcomes

INTRODUCTION

The corpus callosum (CC) is frequently involved in primary central nervous system lymphomas (PCNSLs). In this cohort study, we described the neurocognition of patients with PCNSL-CC and its posttherapeutic evolution.

METHODS

Immunocompetent patients with PCNSL-CC were identified retrospectively at the Pitié-Salpêtrière Hospital. We described their clinical presentation. Neuropsychological test scores (MMSE; digit spans; Free and Cued Selective Reminding Test; Image Oral Naming Test; Frontal Assessment Battery; Trail Making Test; Stroop and verbal fluency tests; Rey's Complex Figure test) and factors impacting them were analyzed.

RESULTS

Twenty-seven patients were included (median age: 67 years, median Karnofsky Performance Status: 70); cognitive impairment and balance disorders were present in 74% and 59%, respectively. At diagnosis, neuropsychological test results were abnormal for global cognitive efficiency (63% of patients), memory (33-80% depending on the test) and executive functions (44-100%). Results for visuospatial and language tests were normal. All patients received high-dose methotrexate-based polychemotherapy, followed in one patient by whole-brain radiotherapy; 67% of patients achieved complete response (CR). With a median follow-up of 48 months (range 6-156), patients in CR had persistent abnormal test results for global cognitive efficiency in 17%, executive function in 18-60%, depending on the test, and memory in 40-60%. Splenium location and age ≥ 60 years were significantly associated with worse episodic memory scores throughout the follow-up.

CONCLUSIONS

PCNSL-CC is associated with frequent cognitive dysfunctions, especially memory impairment, which may recover only partially despite CR and warrant specific rehabilitation. Older age (≥ 60) and splenium location are associated with worse neurocognitive outcomes.

Primary Central Nervous System T-cell Lymphoma as Methotrexate-associated Lymphoproliferative Disorders: Case Report

We report a rare case of primary central nervous system (CNS) lymphoma as methotrexate-associated lymphoproliferative disorders (MTX-LPD). A 75-year-old woman who had been treated for rheumatoid arthritis (RA) with MTX for 3 years was admitted to our hospital complaining of unsteady gait, nausea, and vomiting. T2-weighted image of magnetic resonance imaging (MRI) showed multiple high intensity mass-like lesions including right lateral, frontal and temporal lobes, and right cerebellar hemisphere. We performed surgical biopsy, and the pathological and immunohistochemical examinations identified T-cell lymphoma. The tumor regressed and the symptoms were resolved soon after MTX withdrawal. Primary CNS lymphoma due to MTX-LPD is a rare disease and only eight cases including ours are reported.

Treatment Regimens for Immunocompetent Elderly Patients with Primary Central Nervous System Lymphoma: A Scoping Review

Simple Summary

Most patients diagnosed with primary central nervous system lymphoma (PCNSL) are 60 years or older and tend to have a poor prognosis. Evidence to guide and optimize treatment choices for these vulnerable patients is limited. We performed a scoping review to identify and describe all relevant clinical studies investigating chemotherapies and combinations of chemotherapies (including high-dose chemotherapy followed by autologous stem cell transplantation (HCT-ASCT)) in elderly PCNSL patients. In total, we identified six randomized controlled trials, 26 prospective and 24 retrospective studies (with/without control group). While most studies investigated protocols based on ‘conventional’ chemotherapy treatment, data evaluating HCT-ASCT in the elderly were scarce, and the generalizability of the only RCT published is questionable. Considering the poor prognosis of these patients and their need for more effective treatment options, a thoroughly planned randomized controlled trial comparing HCT-ASCT with ‘conventional’ chemoimmunotherapy is urgently needed to evaluate the efficacy of HCT-ASCT.

Abstract

Background: Most patients diagnosed with primary central nervous system lymphoma (PCNSL) are older than 60 years. Despite promising treatment options for younger patients, prognosis for the elderly remains poor and efficacy of available treatment options is limited. Materials and Methods: We conducted a scoping review to identify and summarize the current study pool available evaluating different types and combinations of (immuno) chemotherapy with a special focus on HCT-ASCT in elderly PCNSL. Relevant studies were identified through systematic searches in the bibliographic databases Medline, Web of Science, Cochrane Library and ScienceDirect (last search conducted in September 2020). For ongoing studies, we searched ClinicalTrials.gov, the German study register and the WHO registry. Results: In total, we identified six randomized controlled trials (RCT) with 1.346 patients, 26 prospective (with 1.366 patients) and 24 retrospective studies (with 2.629 patients). Of these, only six studies (one completed and one ongoing RCT (with 447 patients), one completed and one ongoing prospective single arm study (with 65 patients), and two retrospective single arm studies (with 122 patients)) evaluated HCT-ASCT. Patient relevant outcomes such as progression-free and overall survival and (neuro-)toxicity were adequately considered across almost all studies. The current study pool is, however, not conclusive in terms of the most effective treatment options for elderly. Main limitations were (very) small sample sizes and heterogeneous patient populations in terms of age ranges (particularly in RCTs) limiting the applicability of the results to the target population (elderly). Conclusions: Although it has been shown that HCT-ASCT is probably a feasible and effective treatment option, this approach has never been investigated within a RCT including a wide range of elderly patients. A RCT comparing conventional (immuno) chemotherapy with HCT-ASCT is crucial to evaluate benefit and harms in an un-biased manner to eventually provide older PCNSL patients with the most effective treatment.

Myriad of MR imaging phenotypes of primary central nervous system lymphoma in a cohort of immunocompetent Indian patient population

PCNSL (primary central nervous system lymphoma) is a chemosensitive and radiosensitive tumor, and early diagnosis has a significant impact on management. Unlike many other brain tumors, radical surgical excision of PCNSLs is not indicated because these lesions are highly infiltrative and even partial resection leads to a bad prognosis. The goal of this study is to highlight the unusual radiological presentation of PCNSLs and increase the awareness, familiarity, and global database of our observations that pose a challenge on management.

CXCL13 and CXCL9 CSF Levels in Central Nervous System Lymphoma-Diagnostic, Therapeutic, and Prognostic Relevance

Background: Diagnostic delay and neurologic deterioration are still a problem for the treatment of rapidly progressing CNS lymphoma (CNSL); there is an unmet need for a diagnostic test with a high diagnostic yield and limited risk, minimizing the time to the initiation of effective treatment.

Methods: In this prospective monocentric study, we analyzed the utility of CXCL13 and CXCL9 as diagnostic, therapeutic and prognostic biomarkers for CNSL. Cerebrospinal fluid (CSF) from 155 consecutive patients admitted with brain lesions of various origins was collected. Levels of CXCL13 and CXCL9 were analyzed by ELISA. Additionally, CSF was analyzed during CNSL disease course (relapse, remission, progress) in 17 patients.

Results: CXCL13 and CXCL9 CSF levels were significantly increased in patients with CNSL compared to control patients with lesions of other origin. Using logistic regression and a minimal-p-value approach, a cut-off value of 80 pg/ml for CXCL13 shows high sensitivity (90.7%) and specificity (90.1%) for the diagnosis of active CNSL. CXCL9 at a cut-off value of 84 pg/ml is less sensitive (61.5%) and specific (87.1%). Both cytokines correlate with the clinical course and response to therapy.

Conclusions: Our results confirm the excellent diagnostic potential of CXCL13 and introduce CXCL9 as a novel albeit less powerful marker for PCNSL.

Magnetic Resonance Imaging patterns in central nervous system lymphomas: A pictorial review

Five distinctive Magnetic Resonance Imaging (MRI) patterns of Central Nervous System Lymphomas (CNSL) are introduced in this pictorial essay - in an attempt to differentiate lymphoma from other abnormalities with similar MRI appearance, - namely a. solitary supratentorial, b. multiple supratentorial, c. infratentorial, d. intravascular, and e. extraparencymal. Recognition of a specific imaging pattern on brain MR imaging, may facilitate the early diagnosis and prompt treatment initiation, thus improving prognosis of brain lymphoma.

Traditional and Advanced Neuroimaging Contributions to the Diagnosis and Differential Diagnosis of Central Nervous System Lymphoma Patients Visiting a Comprehensive Medical Center

Introduction:

The diagnosis of Central Nervous System Lymphoma, especially the Primary Central Nervous System Lymphoma is carried out based on brain imaging, thus avoiding an unnecessary extend of surgery. But the traditional imaging techniques, such as Computed Tomography and Magnetic Resonance Imaging, were not satisfactory.

Aims:

This study was conducted to characterize the spectrum of advanced Neuroimaging, such as the advanced Magnetic Resonance Imaging features in the Central Nervous System Lymphoma patients in a comprehensive medical center in Lebanon, and compare them to what has been described in the literature review.

Methods:

It is a retrospective exploratory study of the clinical data and imaging features for patients admitted to the emergency and radiology departments with ages above 10 years, and who were diagnosed histopathologically with intracranial lymphoma. This study may be the first to make a Radiological evaluation of Central Nervous System Lymphoma on the local population of patients over 9 years .

Results:

Results showed that the study of the Computed Tomography and Magnetic Resonance Imaging data of 10 immunocompetent patients with Central Nervous System Lymphoma concurs with the previously described patient populations, except for the gender parameter. Tumors were mostly presented in the fifth or Sixth decade and they could be solitary or multi-focal. Lesions were typically located Preprint submitted to The Open Neuroimaging Journal May 14, 2020 in the supratentorial compartment. On the brain Computed Tomography, the lesions were hyperdense, and in pre-contrast Magnetic Resonance images, the lesions appeared hypointense on T1 and hyperintense on T2-Weighted images, but hypointense with respect to the grey matter. The lesions were also surrounded with a mild to moderate edema as compared to other intracranial neoplasms, such as glioblastomas. Evaluation results showed that on post-contrast Magnetic Resonance images, the majority of lesions exhibited a homogeneous enhancement of 50%. Majority of the lesions also showed a less common heterogeneous ring-like enhancement of 40%, and revealed the uncommon absence of enhancement of 10%. Calcifications, hemorrhage, and necrosis were rare findings and were present in only one patient.

Conclusion:

As a future prospect, studying whether the advanced imaging techniques may provide not only non-invasive and morphological characteristics but also non-invasive biological characteristics and thus accurate diagnosis could be considered.

Conventional MR and DW imaging findings of cerebellar primary CNS lymphoma: comparison with high-grade glioma

Primary central nervous system lymphomas (PCNSLs) and high-grade gliomas (HGGs) arising in the cerebellum is extremely low, making the differential diagnosis difficult or even impossible. The purpose of this study was to define the MR features of cerebellar PCNSL in immunocompetent patients, and to determine whether a combination of conventional MR and DW imaging can assist in the differentiation of PCNSLs and HGGs. Twelve PCNSLs and 15 HGGs confirmed by pathological analysis were retrospectively identified. The apparent diffusion coefficient (ADC) and conventional MRI parameters were compared for differences between PCNSL and HGG groups using the independent sample t test or chi-square test. Both ADC_min and ADC_total values were lower in the PCNSL group than those in the HGG group (ADC_min: 0.53 × 10⁻³ vs. 0.83 × 10⁻³ mm²/sec, P < 0.001; ADC_total: 0.66 × 10⁻³ vs. 0.98 × 10⁻³ mm²/sec, P = 0.001). As for conventional MR features, there were significant difference in the tumor size, enhancement patterns, the presence of cystic changes, edema degree and streak-like edema (all P < 0.01); but there were no significant difference in lesion type, the presence of bleeding, and involvement of brain surface between two groups (P = 0.554, 0.657 and 0.157, respectively). The results revealed that several conventional MR features, including enhancement patterns, branch-like enhancement and streak-like edema may be useful for the differentiation of PCNSL and HGG in cerebellum and, when combined with ADC values, further improve the discriminating ability.

Performance of diffusion and perfusion MRI in evaluating primary central nervous system lymphomas of different locations

Background

Diffusion and perfusion MRI can invasively define physical properties and angiogenic features of tumors, and guide the individual treatment. The purpose of this study was to investigate whether the diffusion and perfusion MRI parameters of primary central nervous system lymphomas (PCNSLs) are related to the tumor locations.

Methods

We retrospectively reviewed the diffusion, perfusion, and conventional MRI of 68 patients with PCNSLs at different locations (group 1: cortical gray matter, group 2: white matter, group 3: deep gray matter). Relative maximum cerebral blood volume (rCBV_max) from perfusion MRI, minimum apparent diffusion coefficients (ADC_min) from DWI of each group were calculated and compared by one-way ANOVA test. In addition, we compared the mean apparent diffusion coefficients (ADC_mean) in three different regions of control group.

Results

The rCBV_max of PCNSLs yielded the lowest value in the white matter group, and the highest value in the cortical gray matter group (P < 0.001). However, the ADC_min of each subgroup was not statistically different. The ADC_mean of each subgroup in control group was not statistically different.

Conclusion

Our study confirms that rCBV_max of PCNSLs are related to the tumor location, and provide simple but effective information for guiding the clinical practice of PCNSLs.

Primary central nervous system lymphoma involving the hypothalamic-pituitary axis: a case series and pooled analysis

PURPOSE

Primary central nervous system lymphoma (PCNSL) involving the hypothalamic-pituitary axis (H-P axis) is a rare intracranial neoplasm. We aimed to determine the unique characteristics and treatment outcomes of patients with PCNSL at the H-P axis and review the literature.

METHODS

We retrospectively reviewed the electronic medical records of patients with PCNSL in our institute from 2000 to 2017. We analyzed patient characteristics, clinicopathologic features, imaging results, and treatment outcomes. Furthermore, we searched the PubMed database and gathered more cases from published studies to analyze patient treatment outcomes.

RESULTS

A total of 488 patients were diagnosed with central nervous system lymphoma at our institute. Seven (1.4%) patients had H-P axis involvement, five had diffuse large B-cell lymphoma, and two had mucosa-associated lymphoid tissue lymphoma. All patients had anterior pituitary lobe dysfunction, and two had posterior lobe dysfunction. The median progression-free survival (PFS) for seven patients was 29.0 (range: 0.9-48.1) months, and the 3-year survival rate was 42.9%. Pooled analysis included 45 patients. The median PFS for these patients was 7.0 months (0.9-52.0), and the 2-year survival rate was 20%. Univariate and multivariate analyses revealed that the patients with visual field defects had better prognosis (p = 0.0153 and 0.043, respectively).

CONCLUSION

PCNSL at the H-P axis is associated with a higher rate of pituitary dysfunction than other parasellar pathologies. PCNSL at the H-P axis has a worse treatment outcome than PCNSL at other sites. However, visual field defect is related to a favorable prognosis in these patients.

Delayed Contrast Enhancement in Magnetic Resonance Imaging and Vascular Morphology of Primary Diffuse Large B-Cell Lymphoma (DLBCL) of the Central Nervous System (CNS): A Retrospective Study

Background

This study aimed to compare the magnetic resonance imaging (MRI) findings of primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS) with delayed contrast enhancement and histological microvessel density (MVD). T1-weighted and T2-weighted contrast-enhanced and non-enhanced brain imaging were used. CNS lymphoma tissue was evaluated using primary antibodies to endothelial cells and smooth muscle cells, and histochemical staining for reticulin fibers and basement membrane, which allowed quantification of the MVD.

Material/Methods

Twenty-one patients with histologically confirmed primary DLBCL of the CNS underwent pre-contrast-enhanced and postcontrast-enhanced MRI. Histology of the CNS lymphoma tissue included immunohistochemical staining with antibodies to CD34 for vascular endothelial cells and alpha smooth muscle actin (ASMA) for vascular smooth muscle cells, and histochemical staining included periodic acid-Schiff (PAS) and silver staining for reticulin fibers to evaluate microvessel density (MVD).

Results

In primary DLBCL of the CNS, a positive correlation was found between the degree of necrosis and the size of the lymphoma (r=0.546, P=0.01). Delayed imaging enhancement was significantly correlated with the number of mature vessels, MVD, basement membrane, and reticulin fibers (r=0.593, 0.466, 0.446 and 0.497, respectively). Standardized β regression coefficient analysis showed that the MVD, PAS-positive structures, the number of mature vessels, and reticulin fibers, were significantly associated with delayed enhancement on MRI (β values, 0.425, 0.409, 0.295, and 0.188, respectively).

Conclusions

In primary DLBCL of the CNS, delayed imaging enhancement on MRI may be due to reduced neovascularization and vascular infiltration by lymphoma cells.

Primary central nervous system post-transplant lymphoproliferative disorders: the spectrum of imaging appearances and differential

OBJECTIVE

Central nervous system post-transplant lymphoproliferative disorder (CNS-PTLD) is a rare disease that presents with non-specific signs and symptoms. The purpose of this article is to present the imaging appearances of CNS-PTLD by magnetic resonance imaging. We highlight the differential diagnostic considerations including primary central nervous system lymphoma, glioblastoma, cerebral abscess, and metastatic disease. This is an important topic to review since in daily practice the diagnosis of CNS-PTLD is often not initially considered when present due to its rarity and the lack of radiologists' familiarity with the disease.

CONCLUSION

Knowing the unique imaging features of CNS-PTLD narrows the differential diagnosis, facilitates the diagnostic work-up, and optimizes making the diagnosis. Advanced MRI data for CNS PTLD is limited but is promising for helping with narrowing the differential diagnosis.

A Case of Sarcoidosis-lymphoma Syndrome: Importance of Brain Biopsy

Sarcoidosis is occasionally associated with malignant lymphoma. Cases of sarcoidosis associated with malignant lymphoma are called sarcoidosis-lymphoma syndrome. We report a 63-year-old man with sarcoidosis associated with primary central nervous system lymphoma (PCNSL). Definitive diagnosis by clinical and radiological findings was difficult. Finally, brain biopsy could produce the correct diagnosis. We could provide appropriate treatment for PCNSL and the patient has survived over 2 years. Thus, it is very important to make an early definitive diagnosis by biopsy for intracranial lesion, because it can prolong survival in patients with sarcoidosis.

Imaging features (CT, MRI, MRS, and PET/CT) of primary central nervous system lymphoma in immunocompetent patients

Background

Because of the low incidence of primary central nervous system lymphoma (PCNSL) in non-HIV individuals and because of the lack of specific clinical manifestations and auxiliary examinations, the disease is easily missed or misdiagnosed.

Objective

To analyze the imaging features of PCNSL in non-HIV patients.

Methods

This was a retrospective study of patients with PCNSL treated between January 2001 and December 2011 at the Naval General Hospital (Beijing, China). All included patients were pathologically diagnosed with PCNSL. Specimens were obtained by stereotactic biopsy and diagnosed by pathological examination. Serological panel had to be negative for HIV.

Results

Out of the 118 patients, 73 (61.9%) were male and 45 (38.1%) were female. Median age was 54 (range 11–83) years. All patients had B cell lymphoma. The lesions showed slightly hyperintense shadows on computed tomography (CT) images, and mostly hyperintense T1 and iso- or hyperintense T2 signals on magnetic resonance imaging (MRI). Most lesions showed patchy enhancement after enhanced scanning, and some had the characteristic “butterfly sign” on enhanced MRI. The magnetic resonance spectroscopy of PCNSL manifested as increased Cho peak, moderately decreased NAA peak, and slightly decreased Cr peak. Positron emission computed tomography indicated high metabolism of ¹⁸F-FDG in PCNSL lesions.

Conclusion

MRI is important in the diagnosis of PCNSL. Understanding the imaging features of PCNSL will help improve its diagnosis in clinics.

Clival Chondrosarcoma Associated With an Intra-Axial Cystic Medullary Lesion Responsive to Steroids

Introduction: Here we present a 75-year-old patient who was admitted with acute-onset right-sided hemiparesis, dysphagia, dysarthria and nystagmus. Repeated MRI scans showed two lesions with contact to one another: one solid stationary extra-axial lesion at the caudal part of the clivus and a rapidly growing intra-axial cystic lesion at the level of the medulla oblongata. Biopsy of the solid lesion demonstrated a low-grade chondrosarcoma, while no tissue sample of the cystic lesion could be retrieved. After initiation of dexamethasone therapy the cystic lesion markedly regressed.

Background: A literature search on published cases with the same combination of a stationary solid extra-axial mass at the caudal part of the clivus and a growing intra-axial cystic mass in the medulla oblongata was negative, indicating that the case described here is both unique and novel.

Discussion: Considering the rapid progression of symptoms and growth on MR-imaging in combination with the marked response to steroids, an inflammatory response linked to the chondrosarcoma is most likely. At the same time other possible explanations as a second neoplasm, an abscess or an ischemic lesion seem unlikely.

Concluding remarks: This case underlines an unusual complication of a rare brainstem tumor and outlines both the differential diagnosis and potential treatment options. For such cystic lesions in combination with chondrosarcoma, a treatment course with steroids should be considered along with surgical exploration necessary to obtain the diagnosis and for potential reduction of mass-effect on the medulla oblongata.

Molecular analysis in liquid biopsies for diagnostics of primary central nervous system lymphoma: Review of literature and future opportunities

Primary central nervous system lymphoma (PCNSL) is an aggressive lymphoma with a poor prognosis, for which accurate and timely diagnosis is of utmost importance. Unfortunately, diagnosis of PCNSL can be challenging and a brain biopsy (gold standard for diagnosis) is an invasive procedure with the risk of major complications. Thus, there is an urgent need for an alternative strategy to diagnose and monitor these lymphomas. Currently, liquid biopsies from cerebrospinal fluid (CSF) are used for cytomorphologic and flow cytometric analysis. Recently, new biomarkers such as genetic mutations and interleukins have been identified in these liquid biopsies, further expanding the diagnostic armamentarium. In this review we present an overview of genetic aberrations (>70) reported in this unique lymphoma. Of these genes, we have selected those that are reported in ≥3 studies. Half of the selected genes are implicated in the NFκB pathway (CARD11, CD79B, MYD88, TBL1XR1 and TNFAIP3), while the other half are not related to this pathway (CDKN2A, ETV6, PIM1, PRDM1 and TOX). Although this underlines the crucial role of the NFκB pathway in PCNSL, CD79B and MYD88 are at present the only genes mentioned in liquid biopsy analysis. Finally, a stepwise approach is proposed for minimally invasive liquid biopsy analysis and work-up of PCNSL, incorporating molecular analysis. Prioritization and refinements of this approach can be constructed based upon multidisciplinary collaboration as well as novel scientific insights.

Primary central nervous system lymphoma in immunocompetent patients: spectrum of findings and differential characteristics

Primary central nervous system (CNS) lymphomas are uncommon and their management differs significantly from that of other malignant tumors involving the CNS. This article explains how the imaging findings often suggest the diagnosis early. The typical findings in immunocompetent patients consist of a supratentorial intraaxial mass that enhances homogeneously. Other findings to evaluate include multifocality and incomplete ring enhancement. The differential diagnosis of primary CNS lymphomas should consider mainly other malignant tumors of the CNS such as glioblastomas or metastases. Primary CNS lymphomas tend to have less edema and less mass effect; they also tend to spare the adjacent cortex. Necrosis, hemorrhage, and calcification are uncommon in primary CNS lymphomas. Although the findings in morphologic sequences are characteristic, they are not completely specific and atypical types are sometimes encountered. Advanced imaging techniques such as diffusion or especially perfusion provide qualitative and quantitative data that play an important role in differentiating primary CNS lymphomas from other brain tumors.

Apparent diffusion coefficient value for a B-cell central nervous system lymphoma in a cat

Case summary

This report involves a 10-year-old male mixed-breed cat with a B-cell central nervous system (CNS) lymphoma. The cat presented with ataxia progressing to left hemiparesis. While haematological findings were normal, serum biochemistry showed a high creatine phosphokinase concentration. MRI revealed a homogeneously enhancing well-demarcated extra-axial lesion involving the region of the left lateral aperture with oedema in left flocculus and left medulla oblongata. On diffusion-weighted imaging, the lesion margins showed marked hyperintensity relative to the right cerebellar hemisphere. On an apparent diffusion coefficient map, the lesion appeared hypointense, with an apparent diffusion coefficient value of 0.57 ± 0.01 × 10⁻³ mm²/s. Cerebrospinal fluid (CSF) analysis and cytology, and genetic analysis of CSF lymphoblasts confirmed a diagnosis of B-cell lymphoma. The owner opted for palliative treatment with prednisolone (1 mg/kg q12h); however, the cat died of dyspnoea 10 days after presentation.

Relevance and novel information

CNS lymphomas, which are the second most common intracranial tumours in cats, are highly infiltrative lesions and radical surgical excision is not recommended. Therefore, accurate diagnosis is crucial. However, contrast-enhanced MRI cannot always differentiate these lesions from other conditions, including other CNS tumours and strokes. To the best of our knowledge, this is the first report to document the diffusion-weighted imaging features and apparent diffusion coefficient value for a feline CNS lymphoma. These findings are expected to improve the diagnostic accuracy of these lesions in cats.

Secondary Central Nerve System Lymphoma With Intratumoral Hemorrhage Suggested as Intravascular Lymphoma by Autopsy: A Case Report

Intravascular large B-cell lymphoma (IVL) is a rare type of extranodal diffuse large B-cell lymphoma (DLBCL), which often infiltrates the central nervous system (CNS) during the clinical course. Cerebral hemorrhage in patients with CNS lymphoma at presentation is rare. Herein, we describe a case of secondary CNS lymphoma with intratumoral hemorrhage, which was suggested as IVL from autopsy findings. A 76-year-old Japanese man with a history of treatment for B-cell non-Hodgkin’s lymphoma was transferred to our hospital in an ambulance for generalized convulsions. Brain CT scan revealed a high-density tumor with edema and intratumoral hemorrhage in the left temporal lobes. He died in a rapid course, and autopsy revealed a focal hemorrhage with diffuse infiltration of lymphoma cells in the left temporal lobe and findings suggestive of IVL. Furthermore, the autopsy revealed a discrepancy in the CD20 immunostaining of lymphoma cells between the brain and other organs. Clinicians should not eliminate CNS lymphoma from the differential diagnosis of intracranial tumor with hemorrhage. Although many patients with IVL have rapidly progressive courses, it is very important to diagnose IVL at the initial onset, even in serious situations, to consider CNS prophylaxis.

Primary central nervous system lymphoma: Retrospective analysis of 34 cases in a single centre

Objective

To retrospectively analyse outcomes in patients with primary central nervous system lymphoma (PCNSL), which is a malignant CNS non-Hodgkin’s lymphoma with a poor prognosis.

Methods

This study retrospectively analysed the treatment and outcomes of patients with PCNSL, which were divided into two groups: surgery (S) group and surgery/biopsy+chemotherapy (SC) group. The latter group was further subdivided into four cohorts based on the treatment regimen: cyclophosphamide, epidoxorubicin, vincristine and prednisone (CHOP), high-dose methotrexate (HDM)+dexamethasone+rituximab (HDM+D+R), HDM+D+temozolomide (HDM+D+T), and HDM+D+R+T.

Results

The study enrolled 34 patients; 10 of which received surgery only. Between the S and SC groups, the median progression-free survival (PFS) and overall survival (OS) of intracranial PCNSLs (n = 32) were 8.5 months versus 29 months, respectively; and 8.5 months versus 54 months, respectively (5-year OS: 10.0% versus 48.7%, respectively; 2-year PFS: 0.0% versus 52.6%, respectively). Comparing the CHOP and HDM-based chemotherapy cohorts, the median PFS and OS were 15 months versus not achieved, respectively, and 25 months versus not achieved, respectively (5-year OS: 20.0% versus 60.8%, respectively; 2-year PFS: 20.0% versus 62.7%, respectively).

Conclusion

Chemotherapy appears to provide a better OS and PFS for patients with PCNSLs compared with surgery alone. HDM+D+T and HDM+D+R+T may be effective choices for PCNSL treatment.

Glioblastoma multiforme presenting with an open ring pattern of enhancement on MR imaging

Background:

Intracerebral ring enhancing lesions can be the presentation of a variety of pathologies, including neoplasia, inflammation, and autoimmune demyelination. Use of a precise diagnostic algorithm is imperative in correctly treating these lesions and minimizing potential adverse treatment effects.

Case Description:

A 55-year-old patient presented to the hospital with complaints of a post-concussive syndrome and a non-focal neurologic exam. Imaging revealed a lesion with an open ring enhancement pattern, minimal surrounding vasogenic edema, and minimal mass effect. Given the minimal mass effect, small size of the lesion, and nonfocal neurological exam, we elected to pursue a comprehensive noninvasive neurologic workup because our differential ranged from inflammatory/infectious to neoplasm. Over the next 8 weeks, the patient's condition worsened, and repeat imaging showed marked enlargement of the lesion with a now closed ring pattern of enhancement with satellite lesions and a magnetic resonance (MR) spectroscopy and perfusion signature suggestive of neoplasm. The patient was taken to surgery for biopsy and debulking of the lesion. Surgical neuropathology examination revealed glioblastoma multiforme.

Conclusion:

The unique open ring enhancement pattern of this lesion on initial imaging is highly specific for a demyelinating process, however, high-grade glial neoplasms can also present with complex and irregular ring enhancement including an open ring sign. Therefore, other imaging modalities should be used, and close follow-up is warranted when the open ring sign is encountered.

Primary central nervous system lymphoma: essential points in diagnosis and management

Primary central nervous system lymphoma (PCNSL) is an extra-nodal non-Hodgkin lymphoma. PCNSL is defined as lymphoma involving the brain, leptomeninges, eyes, or spinal cord without evidence of lymphoma outside the CNS. Treatment includes induction with chemotherapy and consolidation with whole-brain radiotherapy or high-dose chemotherapy supported by autologous stem cell transplantation. High-dose methotrexate is the most important drug in cases with PCNSL, and this drug will be used in combination with small molecules, BTK inhibitors, new monoclonal antibodies, and checkpoint blockers.

Primary diffuse large B-cell lymphoma of the central nervous system: A case report and literature review

The present study reports the clinical diagnosis and management of a patient with primary diffuse large B-cell lymphoma (Bcl) of the central nervous system (CNS). Making an early diagnosis of primary diffuse large Bcl is challenging due to the variable and complicated clinical manifestations of the disease. The relevant literature was reviewed, and high-dose methotrexate, whole brain radiotherapy and highly active antiretroviral therapy was recommended for the patient. The present study elucidates the role of positron emission tomography-computed tomography scans for the diagnosis and management of primary diffuse large Bcl of the CNS, and demonstrates the importance of resection surgery in the management of the disease. Specifically, the present study proposes that resection surgery may be applied in the early stages of disease for patients with a single occupied lesion and increased intracranial pressure.

Lymphomatous involvement of the central nervous system

Lymphoma may arise within the central nervous system (CNS), known as primary CNS lymphoma (PCNSL) or may involve the CNS secondary to systemic disease. Clinical features are non-specific. A provisional diagnosis of PCNSL can be made on imaging, potentially changing the management algorithm from neurosurgical resection to biopsy. PCNSL in immunocompetent patients generally presents late, is solid, is bright on diffusion weighted imaging and shows uniform enhancement. Contiguity with a cerebrospinal fluid (CSF) surface and perivascular enhancement are useful clues. Immunocompromised patients, on the other hand, present earlier and often have multiple, necrotic, haemorrhagic lesions with irregular or rim enhancement. Secondary CNS involvement predominantly affects the leptomeninges. This review illustrates the varied imaging features of CNS lymphoma, atypical presentations, and differential diagnoses.

A rare case of nonenhancing primary central nervous system lymphoma mimic multiple sclerosis

Primary central nervous system lymphoma (PCNSL) is reported to have increased in the last decades. Early diagnosis is crucial for proper management of this tumor. We report a case of a 48-year-old man who was initially diagnosed with multiple sclerosis. Magnetic resonance imaging of the brain revealed multiple lesions with hypersignals in the bilateral basal ganglia and brain stem in T2-weighted image and non-enhancement, while positron emission tomography showed a low uptake of ¹⁸F-fluorodeoxyglucose in the affected brain, indicative of demyelination. However, this individual was correctly diagnosed with PCNSL after biopsy and further histological analysis. Primary central nervous system lymphoma must be considered even when nonenhancing, diffuse lesions are seen on MRI. A visible tumor on imaging is essential to ensure an early brain biopsy and histological diagnosis.

Performance of Apparent Diffusion Coefficient Values and Conventional MRI Features in Differentiating Tumefactive Demyelinating Lesions From Primary Brain Neoplasms

OBJECTIVE

Tumefactive demyelinating lesions (TDLs) remain one of the most common brain lesions to mimic a brain tumor, particularly primary CNS lymphoma (PCNSL) and high-grade gliomas. The purpose of our study was to evaluate the ability of apparent diffusion coefficient (ADC) values and conventional MRI features to differentiate TDLs from PCNSLs and high-grade gliomas.

MATERIALS AND METHODS

Seventy-five patients (24 patients with TDLs, 28 with PCNSLs, and 23 with high-grade gliomas) with 168 brain lesions (70 TDLs, 68 PCNSLs, and 30 high-grade gliomas) who underwent DWI before surgery or therapy were included in the study. Minimum ADC (ADC(min)) and average ADC (ADC(avg)) values were calculated for each lesion. ANOVA and ROC analyses were performed. ROC analyses were also performed for the presence of incomplete rim enhancement and for the number of lesions. Multiple-variable logistic regression with ROC analysis was then performed to evaluate performance in multiple-variable models.

RESULTS

ADC(min) was statistically significantly higher (p < 0.01) in TDLs (mean, 0.886; 95% CI, 0.802-0.931) than in PCNSLs (0.547; 95% CI, 0.496-0.598) and high-grade gliomas (0.470; 95% CI, 0.385-0.555). (All ADC values in this article are reported in units of × 10(-3) mm(2)/s.) ADC(avg) was statistically significantly higher (p < 0.01) in TDLs (mean, 1.362; 95% CI, 1.268-1.456) than in PCNSLs (0.990; 95% CI, 0.919-1.061) but not in high-grade gliomas (1.216; 95% CI, 1.074-1.356). Multiple-variable models showed statistically significant individual effects and superior diagnostic performance on ROC analysis.

CONCLUSION

TDLs can be diagnosed on preoperative MRI with a high degree of specificity; MRI features of incomplete rim enhancement, high ADC values, and a large number of lesions individually increase the probability and diagnostic confidence that a lesion is a TDL.

Modern techniques of magnetic resonance in the evaluation of primary central nervous system lymphoma: contributions to the diagnosis and differential diagnosis

In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence.

This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease.

A practical approach to diseases affecting dentate nuclei

A wide variety of diseases affect the dentate nuclei. When faced with the radiological demonstration of signal changes in the dentate nuclei, radiologists and clinical neurologists have to sieve through the many possibilities, which they do not encounter on a regular basis. This task can be challenging, and therefore, developing a clinical, radiological, and laboratory approach is important. Information on the topic is scattered and the subject has not yet been reviewed. In this review, a combined clinicoradiological approach is presented. The signal changes in T1, T2, fluid-attenuated inversion recovery (FLAIR), diffusion, susceptibility weighted, and gadolinium-enhanced images can give specific or highly suggestive patterns, which are illustrated. The role of computed tomography (CT) in the diagnostic process is discussed. Specific radiological patterns do not exist in a significant proportion of patients where the clinical and laboratory analysis becomes important. In this review, we group the clinical constellations to narrow down the differential diagnosis and highlight the diagnostic clinical signs, such as tendon xanthomas and Kayser-Fleischer rings. As will be seen, a number of these conditions are potentially reversible, and hence, their early diagnosis is desirable. Finally, key diagnostic tests and available therapies are outlined. The practical approach thus begins with the radiologist and winds its way through the clinician, towards carefully selected diagnostic tests defining the therapy options.

Primary central nervous system lymphoma: is absence of intratumoral hemorrhage a characteristic finding on MRI?

Background.

Previous studies have shown that intratumoral hemorrhage is a common finding in glioblastoma multi-forme, but is rarely observed in primary central nervous system lymphoma. Our aim was to reevaluate whether intratumoral hemorrhage observed on T2-weighted imaging (T2WI) as gross intratumoral hemorrhage and on susceptibility-weighted imaging as intratumoral susceptibility signal can differentiate primary central nervous system lymphoma from glioblastoma multiforme.

Patients and methods.

A retrospective cohort of brain tumors from August 2008 to March 2013 was searched, and 58 patients (19 with primary central nervous system lymphoma, 39 with glioblastoma multiforme) satisfied the inclusion criteria. Absence of gross intratumoral hemorrhage was examined on T2WI, and an intratumoral susceptibility signal was graded using a 3-point scale on susceptibility-weighted imaging. Results were compared between primary central nervous system lymphoma and glioblastoma multiforme, and values of P < 0.05 were considered significant.

Results.

Gross intratumoral hemorrhage on T2WI was absent in 15 patients (79%) with primary central nervous system lymphoma and 23 patients (59%) with glioblastoma multiforme. Absence of gross intratumoral hemorrhage could not differentiate between the two disorders (P = 0.20). However, intratumoral susceptibility signal grade 1 or 2 was diagnostic of primary central nervous system lymphoma with 78.9% sensitivity and 66.7% specificity (P < 0.001), irrespective of gross intratumoral hemorrhage.

Conclusions.

Low intratumoral susceptibility signal grades can differentiate primary central nervous system lymphoma from glioblastoma multiforme. However, specificity in this study was relatively low, and primary central nervous system lymphoma cannot be excluded based solely on the presence of an intratumoral susceptibility signal.

Evolution of a Pediatric Primary Cerebral ALK-1-Positive Anaplastic Large Cell Lymphoma on Serial MRI

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare central nervous system tumor, especially in the pediatric population. There are fewer than 20 described cases of pediatric primary central nervous system anaplastic large cell lymphoma. The child described in our case report demonstrated a dramatic evolution of this tumor in the first 4 weeks on serial imaging.

METHODS

Serial MRI imaging was performed followed by biopsy and chemotherapy.

RESULTS

Initial imaging revealed a T2 hyperintense lesion in the frontal lobe with abnormally enhancing sulci and minimal surrounding edema and diffusion restriction. Serial imaging revealed progressive increase in the degree of gadolinium enhancement, and the hyperintense T2 edema progressed markedly to exert mass effect. The lesion itself grew marginally. Biopsy revealed an anaplastic large cell lymphoma, only described in 14 previous pediatric patient case reports. The patient was successfully treated with chemotherapy and autologous stem cell transplant.

CONCLUSIONS

Our case demonstrates the rapidity with which a PCNSL lesion can develop, and the evolution of the imaging characteristics prior to definitive diagnosis and treatment. Serial imaging by MRI may help differentiate the behavior of a PCNSL from other imitating lesions.

Imaging of brain tumors

Neuroimaging plays a crucial role in diagnosis of brain tumors and in the decision-making process for therapy. Functional imaging techniques can reflect cellular density (diffusion imaging), capillary density (perfusion techniques), and tissue biochemistry (magnetic resonance [MR] spectroscopy). In addition, cortical activation imaging (functional MR imaging) can identify various loci of eloquent cerebral cortical function. Combining these new tools can increase diagnostic specificity and confidence. Familiarity with conventional and advanced imaging findings facilitates accurate diagnosis, differentiation from other processes, and optimal patient treatment. This article is a practical synopsis of pathologic, clinical, and imaging spectra of most common brain tumors.

Differentiation of primary central nervous system lymphoma from high-grade glioma and brain metastases using susceptibility-weighted imaging

BACKGROUND AND PURPOSE

Conventional MRI is often difficult to distinguish between primary central nervous system lymphomas (PCNSLs), high-grade gliomas and brain metastases due to the similarity of their appearance. The aim of this study was to investigate whether the susceptibility-weighted imaging (SWI) has higher sensitivity than conventional MRI in detecting hemorrhage between PCNSLs, high-grade gliomas and brain metastases, and can be used to differentiate the diagnosis between these tumors.

METHODS

The number of lesions with hemorrhage was quantified by both the conventional MR imaging and SWI. The number of micro-hemorrhage and vessels within lesions were counted on SWI.

RESULTS

The detection rate of hemorrhage on SWI was significantly higher than that on the conventional MR imaging. The intralesional hemorrhagic burden and the number of the vessels within lesions detected by SWI were significantly higher in high-grade gliomas and brain metastases than those in PCNSLs. There was no significant difference in these two parameters between high-grade gliomas and brain metastases. The best predictor to differentiate PCNSLs from high-grade gliomas and brain metastases was intralesional vessel number that yielded the best ROC characteristics and highest classification accuracy.

CONCLUSIONS

SWI is useful in differentiating of PCNSLs from high-grade gliomas and brain metastases.

Neuroimaging of primary central nervous system lymphoma in immunocompetent patients: comparison of recent and previous findings

The typical neuroimaging features of primary central nervous system lymphoma (PCNSL) have been described as single or multiple intra-axial, homogenous, contrast-enhancing lesions with marked perilesional edema and restricted diffusion, usually contacting the cerebrospinal fluid surface. Necrosis, peripheral enhancement, hemorrhages, and calcifications are unusual. Recently, some of our patients with PCNSL have had atypical neuroimaging features even before treatment. In this article, we review the neuroimaging characteristics of PCNSL in immunocompetent patients and analyzed how imaging findings over the last 10 years differ from those from more than 10 years ago. Neuroimaging findings suggest that PCNSL is a disease that affects the entire brain. Although some imaging findings are characteristic of PCNSL, the frequency of atypical findings on conventional neuroimaging is increasing. Atypical neuroimaging findings do not rule out PCNSL, even in immunocompetent patients.

A Case of Primary T-Cell Central Nervous System Lymphoma: MR Imaging and MR Spectroscopy Assessment

Primary central nervous system lymphomas (PCNSLs) are mainly B-cells lymphomas. A risk factor for the development of PCNSL is immunodeficiency, which includes congenital disorders, iatrogenic immunosuppression, and HIV. The clinical course is rapidly fatal; these patients usually present signs of increased intracranial pressure, nausea, papilledema, vomiting, and neurological and neuropsychiatric symptoms. PCNSL may have a characteristic appearance on CT and MR imaging. DWI sequences and MR spectroscopy may help to differentiate CNS lymphomas from other brain lesions. In this paper, we report a case of a 23-year-old man with T-primary central nervous system lymphoma presenting with a mass in the right frontotemporal lobe. We describe clinical, CT, and MRI findings. Diagnosis was confirmed by stereotactic biopsy of the lesion.