Primary leptomeningeal lymphoma: International Primary CNS Lymphoma Collaborative Group report

Diagnostics and treatment delay in primary central nervous system lymphoma: What the neurosurgeon should know

PURPOSE

The gold standard for diagnostics in primary central nervous system lymphoma (PCNSL) is histopathological diagnosis after stereotactic biopsy. Yet, PCNSL has a multidisciplinary diagnostic work up, which associated with diagnostic delay and could result in treatment delay. This article offers recommendations to neurosurgeons involved in clinical decision-making regarding (novel) diagnostics and care for patients with PCNSL with the aim to improve uniformity and timeliness of the diagnostic process for patients with PCNSL.

METHODS

We present a mini review to discuss the role of stereotactic biopsy in the context of novel developments in diagnostics for PCNSL, as well as the role for cytoreductive surgery.

RESULTS

Cerebrospinal fluid-based diagnostics are supplementary and cannot replace stereotactic biopsy-based diagnostics.

CONCLUSION

Histopathological diagnosis after stereotactic biopsy of the brain remains the gold standard for diagnosis. Additional diagnostics should not be a cause of diagnostic delay. There is currently no sufficient evidence supporting cytoreductive surgery in PCNSL, with recent studies showing contradictive data and suboptimal study designs.

Spatial transcriptomics analysis identifies a tumor-promoting function of the meningeal stroma in melanoma leptomeningeal disease

Leptomeningeal disease (LMD) remains a rapidly lethal complication for late-stage melanoma patients. Here, we characterize the tumor microenvironment of LMD and patient-matched extra-cranial metastases using spatial transcriptomics in a small number of clinical specimens (nine tissues from two patients) with extensive in vitro and in vivo validation. The spatial landscape of melanoma LMD is characterized by a lack of immune infiltration and instead exhibits a higher level of stromal involvement. The tumor-stroma interactions at the leptomeninges activate tumor-promoting signaling, mediated through upregulation of SERPINA3. The meningeal stroma is required for melanoma cells to survive in the cerebrospinal fluid (CSF) and promotes MAPK inhibitor resistance. Knocking down SERPINA3 or inhibiting the downstream IGR1R/PI3K/AKT axis results in tumor cell death and re-sensitization to MAPK-targeting therapy. Our data provide a spatial atlas of melanoma LMD, identify the tumor-promoting role of meningeal stroma, and demonstrate a mechanism for overcoming microenvironment-mediated drug resistance in LMD.

The spectrum of malignant diagnoses in cerebrospinal fluid cytology from an adult population: a multi-institutional retrospective review

INTRODUCTION

Limited updated literature exists about the prevalence and spectrum of malignancies involving cerebrospinal fluid (CSF). In this multi-institutional study, we review our experience with focus on first time malignancy diagnosis in CSF samples of adults.

MATERIALS AND METHODS

Institutional databases at 4 academic centers were queried retrospectively for CSFs over a 10-year period. The following data elements were collected: total # of CSFs, total # of CSFs with a malignant diagnosis; for each patient with a first time CSF diagnosis of malignancy: age, gender, diagnosis, prior history of malignancy, and ancillary studies.

RESULTS

Twenty-four thousand one hundred forty-two CSFs were collected with a positive for malignancy rate of 2.3% (n = 551). Out of 347 (1.4%) adults with a first-time diagnosis of CSF malignancy 182 (52%) were female (age range: 19-89/mean: 57) and 165 (48%) were male (age range: 20-95/mean: 60). Hematolymphoid malignancies (48%, n = 168) were overall the most common neoplasm. In women, metastatic carcinomas (63%, n = 114) were the leading malignancy, of which the majority were breast primaries. In men, lymphomas/leukemias (64%, n = 106) were the leading malignancy, of which the majority were B-cell lymphomas. Ancillary studies aided the final diagnosis in 110 (32%) cases. For 286 (82%) cases, a prior history of malignancy was available to correlate CSF findings.

CONCLUSIONS

A malignancy diagnosis in the CSF of adults is rare. The most common malignancies in females and males are metastatic breast carcinoma and hematolymphoid malignancies, respectively. Metastatic neoplasms account for the majority, with primary central nervous system neoplasms being quite uncommon. History of malignancy and ancillary tests can be helpful.

Primary leptomeningeal CD30 positive diffuse large B cell lymphoma disguise as meningioma in a young adult: a case report

BACKGROUND

Primary leptomeningeal lymphoma (PLML) without brain parenchymal involvement or systemic disease is very rare, comprising of approximately 7% of all primary central nervous system lymphomas (PCNSL). PLML is a diagnosis of exclusion which should be confirmed on biopsy after ruling out metastasis from systemic lymphomas and dissemination from PCNSL.

CASE DESCRIPTION

A 21-year-old patient presented with the chief complaints of headache, diplopia, decreased vision for five months, and a swelling on the left side of the forehead for four months. On radiology, a large, lobulated, extra-axial mass lesion along the left frontal region with its base towards dura noted. No parenchymal or subependymal CNS lesions were found on CT/MRI. Histopathology was reported as primary leptomeningeal CD30 positive diffuse large B cell lymphoma.

CONCLUSIONS

PLML is a very rare meningeal tumor that requires a very high index of suspicion and is always a diagnosis of exclusion.

Spatial transcriptomics analysis identifies a unique tumor-promoting function of the meningeal stroma in melanoma leptomeningeal disease

Leptomeningeal disease (LMD) remains a rapidly lethal complication for late-stage melanoma patients. The inaccessible nature of the disease site and lack of understanding of the biology of this unique metastatic site are major barriers to developing efficacious therapies for patients with melanoma LMD. Here, we characterize the tumor microenvironment of the leptomeningeal tissues and patient-matched extra-cranial metastatic sites using spatial transcriptomic analyses with in vitro and in vivo validation. We show the spatial landscape of melanoma LMD to be characterized by a lack of immune infiltration and instead exhibit a higher level of stromal involvement. We show that the tumor-stroma interactions at the leptomeninges activate pathways implicated in tumor-promoting signaling, mediated through upregulation of SERPINA3 at the tumor-stroma interface. Our functional experiments establish that the meningeal stroma is required for melanoma cells to survive in the CSF environment and that these interactions lead to a lack of MAPK inhibitor sensitivity in the tumor. We show that knocking down SERPINA3 or inhibiting the downstream IGR1R/PI3K/AKT axis results in re-sensitization of the tumor to MAPK-targeting therapy and tumor cell death in the leptomeningeal environment. Our data provides a spatial atlas of melanoma LMD, identifies the tumor-promoting role of meningeal stroma, and demonstrates a mechanism for overcoming microenvironment-mediated drug resistance unique to this metastatic site.

Central Nervous System Lymphoma

Central nervous system lymphoma (CNSL) is a rare and aggressive malignancy that primarily affects the brain, spinal cord, and meninges. This article provides a comprehensive overview of the current understanding of CNSL encompassing its epidemiology, pathophysiology, clinical presentation, diagnosis, treatment modalities, and prognosis. Although the main focus is on primary CNS lymphoma (PCNSL), ocular lymphoma, primary leptomeningeal lymphoma, and secondary CNS lymphoma are also discussed. The pathobiology of CNSL involves the infiltration of malignant lymphocytes within the CNS parenchyma or leptomeninges. Various risk factors and immunological mechanisms contribute to its development, including immunodeficiency states, chronic inflammation, and genomic alterations. Accurate diagnosis is crucial for appropriate management, given the heterogeneous clinical presentation. The neuroimaging, systemic imaging, and other modalities for diagnosis and evaluation for extent of disease involvement will be discussed. Additionally, the importance of histopathological examination, cerebrospinal fluid (CSF) analysis, and molecular testing in confirming the diagnosis and guiding treatment decisions are highlighted. The treatment landscape for CNSL has evolved significantly. Therapeutic approaches encompass a multimodal strategy combining high-dose methotrexate-based chemotherapy, consolidation with whole-brain radiation therapy, and high-dose chemotherapy with stem cell rescue. Recent advancements in targeted therapies and immunomodulatory agents offer promising avenues for future treatment options. We review the clinical outcomes and prognostic factors influencing the survival of CNSL patients, including age, performance status, disease stage, and genetic abnormalities.

The Spectrum of Headache in Leptomeningeal Metastases: A Comprehensive Review with Clinical Management Guidelines

PURPOSE OF REVIEW

Headaches are a common, oftentimes debilitating symptom in patients with leptomeningeal metastases.

RECENT FINDINGS

The third edition of the International Classification of Headache Disorders provides a useful diagnostic framework for headaches secondary to leptomeningeal metastases based on the temporal relationship of headache with disease onset, change in headache severity in correlation with leptomeningeal disease burden, and accompanying neurologic signs such as cranial nerve palsies and encephalopathy. However, headaches in patients with leptomeningeal metastases can be further defined by a wide range of varying cancer- and treatment-related pathophysiologies, each requiring a tailored approach. A thorough review of the literature and expert opinion on five observed headache sub-classifications in patients with leptomeningeal metastases is provided, with attention to necessary diagnostic testing, recommended first-line treatments, and prevention strategies.

Pretreatment findings on magnetic resonance imaging in primary central nervous system lymphoma may predict overall survival duration

BACKGROUND

and purpose: Primary central nervous system lymphoma (PCNSL) lesions often show avid contrast enhancement on T1-weighted contrast-enhanced MRI sequences. However, several case reports and a clinical study have described PCNSL in patients with no contrast enhancement on MRI. We assessed whether overall survival (OS) time was related to any tumor characteristics (lesion location, volume, and number; contrast enhancement; necrosis; proximity to the subarachnoid space; and edema) on MRI in patients with PCNSL.

MATERIALS AND METHODS

We retrospectively reviewed records (MRI features, pathology, and survival data) of all patients at our institution with PCNSL who had been seen from, 2007 through 2017, and had undergone pretreatment MRI.

RESULTS

We identified 79 patients (42 men, 37 women) with a mean age at diagnosis of 61.7 ± 10.4 years. The mean OS duration was 44.6 ± 41.7 months. The most common pathological diagnosis (74 patients) was diffuse large B-cell lymphoma. No associations were found between OS time and lesion location, volume, and number; contrast enhancement; necrosis; proximity to the subarachnoid space; or edema. However, a sole patient with non-enhancing PCNSL on MRI was found to have low-grade disease, with prolonged survival (>83 months). Several other patients with leptomeningeal disease had a mean OS time of 80 months. Patients with hemorrhagic lesions had a mean OS of 25.5 months.

CONCLUSIONS

The survival time for patients with PCNSL may be longer than previously thought, especially for patients with leptomeningeal seeding and lesions with hemorrhagic components Also, non-enhancing tumors may be less aggressive than enhancing tumors.

Primary Central Nervous System Lymphoma Presenting as Isolated Multiple Cranial Neuropathies: An Extremely Rare Case

Primary central nervous system lymphoma (PCNSL) is an uncommon malignancy of B-cell origin that typically involves the brain, eyes, and spinal cord without systemic spread. PCNSL typically involves the cerebral hemispheres, basal ganglia, or periventricular region. Isolated leptomeningeal PCNSL without any evidence of parenchymal involvement is very rare. We present a very unusual case of PCNSL presenting as persistent bilateral Bell's palsy and trigeminal neuralgia with magnetic resonance imaging (MRI) brain showing significantly hypertrophied enhancing bilateral facial and trigeminal nerves.

Leptomeningeal Metastasis: A Review of the Pathophysiology, Diagnostic Methodology, and Therapeutic Landscape

The present review aimed to establish an understanding of the pathophysiology of leptomeningeal disease as it relates to late-stage development among different cancer types. For our purposes, the focused metastatic malignancies include breast cancer, lung cancer, melanoma, primary central nervous system tumors, and hematologic cancers (lymphoma, leukemia, and multiple myeloma). Of note, our discussion was limited to cancer-specific leptomeningeal metastases secondary to the aforementioned primary cancers. LMD mechanisms secondary to non-cancerous pathologies, such as infection or inflammation of the leptomeningeal layer, were excluded from our scope of review. Furthermore, we intended to characterize general leptomeningeal disease, including the specific anatomical infiltration process/area, CSF dissemination, manifesting clinical symptoms in patients afflicted with the disease, detection mechanisms, imaging modalities, and treatment therapies (both preclinical and clinical). Of these parameters, leptomeningeal disease across different primary cancers shares several features. Pathophysiology regarding the development of CNS involvement within the mentioned cancer subtypes is similar in nature and progression of disease. Consequently, detection of leptomeningeal disease, regardless of cancer type, employs several of the same techniques. Cerebrospinal fluid analysis in combination with varied imaging (CT, MRI, and PET-CT) has been noted in the current literature as the gold standard in the diagnosis of leptomeningeal metastasis. Treatment options for the disease are both varied and currently in development, given the rarity of these cases. Our review details the differences in leptomeningeal disease as they pertain through the lens of several different cancer subtypes in an effort to highlight the current state of targeted therapy, the potential shortcomings in treatment, and the direction of preclinical and clinical treatments in the future. As there is a lack of comprehensive reviews that seek to characterize leptomeningeal metastasis from various solid and hematologic cancers altogether, the authors intended to highlight not only the overlapping mechanisms but also the distinct patterning of disease detection and progression as a means to uniquely treat each metastasis type. The scarcity of LMD cases poses a barrier to more robust evaluations of this pathology. However, as treatments for primary cancers have improved over time, so has the incidence of LMD. The increase in diagnosed cases only represents a small fraction of LMD-afflicted patients. More often than not, LMD is determined upon autopsy. The motivation behind this review stems from the increased capacity to study LMD in spite of scarcity or poor patient prognosis. In vitro analysis of leptomeningeal cancer cells has allowed researchers to approach this disease at the level of cancer subtypes and markers. We ultimately hope to facilitate the clinical translation of LMD research through our discourse.

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.

Primary Leptomeningeal Lymphoma: Clinicopathologic Features of 2 Rare Phenotypes

Primary leptomeningeal lymphoma is exceedingly rare. We describe 2 rare lymphoma cases with exclusive leptomeningeal disease: 1 ALK-positive (ALK+) anaplastic large cell lymphoma (ALCL) and 1 primary effusion lymphoma (PEL). Case 1: A 19-year-old man presented with symptoms concerning for leptomeningitis. Cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis. Spine MRI demonstrated pial enhancement from T10 through the conus medullaris and cauda equina enhancement/thickening. A biopsy showed leptomeningeal involvement by large lymphoma cells with hallmark cells and brisk mitotic activity. By immunohistochemistry, cells were CD7/CD30-positive with cytoplasmic ALK staining. No systemic disease was identified. The diagnosis of primary leptomeningeal ALK+ ALCL was made. Despite 2 CSF relapses requiring systemic therapy and autologous bone marrow transplant, the patient was in complete clinical remission 9 years after the diagnosis. Case 2: A 60-year-old, human immunodeficiency virus-positive man presented with symptoms suggestive of leptomeningitis. Brain MRIs revealed multifocal, supratentorial, and infratentorial leptomeningeal enhancement. A right frontal biopsy demonstrated leptomeningeal involvement by large lymphoma cells negative for B-cell immunostains, but CD138, MUM-1, and HHV8-positive, with aberrant CD3 expression. EBV-encoded RNA in situ hybridization was positive. In absence of solid lesions/extracranial involvement, the diagnosis of leptomeningeal PEL was rendered. Despite initial complete remission after chemotherapy, the patient died 9 months later.

Primary dural lymphoma: Case report

Primary Dural lymphoma (PDL) is a rare pathology that occurs in immunocompetent patients. In such cases, these lesions may mimic more common intracranial tumors. We present the case of a patient who presented an intra cranial hypertension syndrome; the brain MRI showed a tissular mass that we took for a meningioma; upon surgical intervention, an occult mass was discovered. Major excision and immunohistochemistry demonstrated PDL. Our case report highlights the rarity of these pathology and the importance of combined surgery and medical treatment, as the latter can be treated with chemoradiation with good clinical outcomes.

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Primary dural lymphoma (PDL) is a rare pathology that occurs in immunocompetent patients.

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We present the case of a patient who presented an intra cranial hypertension syndrome; the brain MRI showed a tissular mass that we took for a meningioma; upon surgical intervention, an occult mass was discovered.

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Our case report highlights the rarity of these pathology and the importance of combined surgery and medical treatment.

Synchronous pulmonary adenocarcinoma and primary leptomeningeal large B-cell lymphoma-Diagnostic challenge in cerebrospinal fluid: A brief report

Lung cancer is one of the most common causes of cancer-related deaths worldwide. During or after the treatment of lung cancer, patients might develop another malignant neoplasm. To our knowledge, synchronous pulmonary adenocarcinoma and leptomeningeal large B-cell lymphoma have not been reported in the literature. Herein, we report the first case of synchronous pulmonary adenocarcinoma and primary leptomeningeal lymphoma, which is challenging in cytological diagnosis using cerebrospinal fluid (CSF). Knowledge of this rare situation by cytopathologists might avoid misdiagnosis or erroneous tumor classification during the cytological diagnosis of CSF in the future.

Central Nervous System Lymphoma: Novel Therapies

OPINION STATEMENT

Primary central nervous system lymphomas (PCNSLs) are very rare neoplasms and continue to be challenging to treat. While high-dose methotrexate (HD-MTX)-based regimens are the currently accepted standard first-line therapy for newly diagnosed patients, the optimal induction therapies are still unknown. The role of consolidation therapies continues to evolve with a variety of chemotherapy regimens, including high-dose chemotherapy with stem cell rescue and reduced or deferred whole brain radiotherapy being used. Importantly, several recent advances have been made in the treatment of PCNSL. The incorporation of targeted therapy and immune therapy remain promising strategies. Several agents, successfully used in treatment of systemic lymphomas, have shown activity in PCNSL, frequently leading to durable responses in the relapsed/refractory patients. Many ongoing studies will likely lead to a better understanding of the roles of these treatments, especially as the first line and potentially also as maintenance. In addition, the use of molecular profiling to predict disease response to targeted agents and understand relapse patterns will become increasingly important. Clinical trials in PCNSL are critical yet frequently challenging to conduct given the rarity of the condition and lack of suitable subjects. Therefore, multi-institutional and international collaboration is of utmost importance to accelerate progress in understanding the biology and design better treatments for this disease. It is critical to consider patients of all demographics in the design and study of future treatment algorithms to have the largest impact on patient care and outcomes.

Different facets of intracranial central nervous system lymphoma and its imaging mimics

Lymphomas of the central nervous system (CNS) are broadly classified into primary CNS lymphoma (PCNSL) and secondary CNS lymphoma (SCNSL). PCNSL refers to lymphoma restricted to the brain, leptomeninges, spinal cord, or eyes without evidence of it outside the CNS at primary diagnosis, while SCNSL refers to secondary CNS involvement by systemic lymphoma. The brain is the most common site of involvement and intracranial CNS lymphoma has a highly variable imaging appearance and varies according to the patient’s clinical profile and immunity. This pictorial essay aims to illustrate the different facets of intracranial CNS lymphomas on neuroimaging. This enables radiologists to be familiarized with their key diagnostic features and differentiate from their differential diagnoses, leading to early diagnosis, and treatment.

A Case of Primary Leptomeningeal Lymphoma Presenting with Hydrocephalus Characterized by Disproportionately Large Fourth Ventricle

Primary leptomeningeal malignant lymphoma (PLML) is a rare variant of primary central nerve system malignant lymphoma (PCNSL) which is restricted to leptomeninges. The lesions of PLML can often be detected as abnormal enhancement on the surface of central nervous system or the ventricular wall on magnetic resonance imaging (MRIs). Cerebrospinal fluid (CSF) evaluation together with such MRI findings provides the definitive diagnosis of PLML. Here, we present a 45-year-old female case of PLML in which hydrocephalus with disproportionately large fourth ventricle was observed at presentation with gait instability. Head MRI revealed no abnormal enhancement and CSF cytology was negative, leaving the cause of hydrocephalus undetermined. Endoscopic third ventriculostomy (ETV) was effectively performed for hydrocephalus and her symptoms disappeared. Nearly 2 years later, she was brought to emergent room due to unconsciousness with the recurrence of hydrocephalus. MRI showed expanded fourth ventricle and abnormal enhancement on the ventricular wall. The endoscopic surgery for improving CSF flow was successful and inflammatory change was endoscopically observed on the ventricular wall involving aqueduct. Pathological diagnosis of the specimen from the ventricular wall proved B-cell lymphoma. Because neither brain parenchymal masses nor systemic tumors were identified, she was diagnosed with PLML and treated by high-dose methotrexate. She was in a stable state 2 years after the diagnosis of PLML. We report and discuss the characteristics of this case.

Primary Leptomeningeal B-cell Lymphoma in an Immunocompetent Adult: Case Report

Primary leptomeningeal lymphoma (PLML) is a rare disease, comprising less than 1% of all lymphomas. Clinical manifestations include headache, encephalopathy, ataxia, cranial nerve palsy, and myelitis. Diagnosis requires a combination of magnetic resonance images (MRI), cytology, flow cytometry of cerebrospinal fluid (CSF), and an extensive workup to rule out systemic lymphoma.

We describe the case of a 49-year-old man who developed subacute onset headache, encephalopathy, and blindness. Whole-body examinations, including a bone marrow trephine biopsy, excluded systemic lymphoma. Brain MRI showed leptomeningeal enhancement. Cytology and flow cytometry of CSF found a clonal B-cell population making a diagnosis of PLML. He began treatment with rituximab and high-dose methotrexate (HD-MTX), with progressive clinical improvement. CSF analysis after two cycles and one intrathecal methotrexate dose was normal.

Brain and spinal MRI images plus CSF analysis, along with an extensive workup to exclude systemic lymphoma, are necessary to diagnose PLM. Early treatment with HD-MTX alone or in combination with rituximab improves clinical outcomes.

Diagnosis and management of primary central nervous system lymphoma: a Consensus Practice Statement from the Australasian Lymphoma Alliance

Primary central nervous system lymphoma is a clinicopathological disease entity that accounts for 1 % of all non-Hodgkin lymphoma (NHL). Advanced patient age, adverse disease biology and complexities of diagnosis and treatment render outcomes markedly inferior to systemic NHL. Despite this, an increasing evidence base including limited randomised controlled clinical trial data is informing optimal therapeutic strategies with methotrexate-based induction chemotherapy schedules and intensified consolidation in selected patients. This practice statement represents an evidence-based review of the literature and has been devised to assist healthcare professionals in the diagnosis and management of this disease. This article is protected by copyright. All rights reserved.

Chronic Lymphocytic Leukaemia: Rare Involvement of the Central Nervous System

Involvement of the central nervous system, although uncommon, is one of the most frequent extramedullary manifestations of chronic lymphocytic leukaemia (CLL). Various conditions can lead to neurological symptoms in CLL patients and distinguishing between clinically significant CLL involvement of the CNS and other aetiologies can be challenging.

The authors report the case of a 90-year-old woman with a previous diagnosis of low-risk CLL who presented to the emergency room with altered mental status. After the most frequent causes were ruled out and considering the underlying disease, CNS infiltration by clonal B-cells was hypothesised and later confirmed. Treatment was initiated, but the patient died soon afterwards.

Treatment of Primary CNS Lymphoma: Maximizing Clinical Benefit, Minimizing Neurotoxicity

PURPOSE OF REVIEW

The optimal treatment for newly diagnosed and refractory or relapsed primary central nervous system lymphoma (PCNSL) is not fully defined. We review the epidemiology, clinical presentation, and current management strategies for newly diagnosed PCNSL as well as emerging treatments for refractory and relapsed disease.

RECENT FINDINGS

In recent decades, the incidence of PCNSL has increased in the elderly population. With advancements in chemotherapy for PCNSL, survival has improved. However, outcomes remain inferior when compared with other forms of extranodal lymphoma. Additionally, treatments can be associated with clinically significant neurotoxicities. Despite advances in the treatment of PCNSL, current treatment regimens remain suboptimal in terms of response rates and neurotoxicity. Well-tolerated agents, especially for the elderly, are still needed.

Primary leptomeningeal lymphoma masquerading as infectious tubercular meningitis

Primary central nervous system lymphoma (PCNSL) is infrequent and often poses diagnostic conundrums due to its protean manifestations. We present the case of a South Asian young man presenting with raised intracranial pressure and a lymphocytic cerebrospinal fluid (CSF) with pronounced hypoglycorrhachia. Progression of the neuro-ophthalmic signs while on early stages of antitubercular treatment led to additional investigations that produced a final diagnosis of primary leptomeningeal lymphoma. Treatment with chemoimmunotherapy (methotrexate, cytarabine, thiotepa and rituximab (MATRix)) achieved full radiological remission followed by successful autologous transplant. This case highlights the difficulties and diagnostic dilemmas when PCNSL presents as a chronic meningeal infiltrative process. While contextually this CSF is most often indicative of central nervous system tuberculosis and justifies empirical treatment initiation alone, it is essential to include differential diagnoses in the investigation work-up, which also carry poor prognosis without timely treatment. High suspicion, multidisciplinary collaboration and appropriate CSF analysis were the key for a correct diagnosis.

Local Control of Primary Dural Central Nervous System Lymphoma Achieved With Radiotherapy

Primary central nervous system lymphomas (PCNSL) are extranodal non-Hodgkin's lymphomas (NHL) confined to the brain, leptomeninges, eyes, or spinal cord. Primary leptomeningeal lymphoma (PLML), without parenchymal involvement, synchronous cerebrospinal, or systemic disease is rare. The estimated incidence of PLML is 7% of all PCNSL, which in turn accounts for about 2% of all primary brain tumors and 0.8% of all lymphomas.

The incidence of PCNSL in Western countries is approximately five cases per million inhabitants per year, and less than 5% of all primary tumors of the central nervous system (CNS), although it is worth mentioning that the incidence seems to be increasing. The largest series of cases reported in the medical literature collect information from no more than nine patients; in these series, the median age at diagnosis is 57 years; in general, all patients present with cerebrospinal fluid alteration, and the median overall survival rate is close to eight months.

With our case series, we aim at sharing the experience of four patients diagnosed and treated at the National Cancer Institute between 2010 and 2020, establishing a correlation of the clinical, imaging, and histopathological presentation, the response to treatment based on radiotherapy and chemotherapy, and the clinical outcomes reported in the medical records.

Positron emission tomography and magnetic resonance imaging in primary central nervous system lymphoma-a narrative review

This review addresses the challenges of primary central nervous system (CNS) lymphoma diagnosis, assessment of treatment response, and detection of recurrence. Primary CNS lymphoma is a rare form of extra-nodal non-Hodgkin lymphoma that can involve brain, spinal cord, leptomeninges, and eyes. Primary CNS lymphoma lesions are most commonly confined to the white matter or deep cerebral structures such as basal ganglia and deep periventricular regions. Contrast-enhanced magnetic resonance imaging (MRI) is the standard diagnostic modality employed by neuro-oncologists. MRI often shows common morphological features such as a single or multiple uniformly well-enhancing lesions without necrosis but with moderate surrounding edema. Other brain tumors or inflammatory processes can show similar radiological patterns, making differential diagnosis difficult. [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) has selected utility in cerebral lymphoma, especially in diagnosis. Primary CNS lymphoma can sometimes present with atypical findings on MRI and FDG PET, such as disseminated disease, non-enhancing or ring-like enhancing lesions. The complementary strengths of PET and MRI have led to the development of combined PET-MR systems, which in some cases may improve lesion characterization and detection. By highlighting active developments in this field, including advanced MRI sequences, novel radiotracers, and potential imaging biomarkers, we aim to spur interest in sophisticated imaging approaches.

Rheumatoid meningitis as a complication of long-standing rheumatoid arthritis: a case treated with rituximab

Rheumatoid meningitis is a rare complication of long-standing rheumatoid arthritis. We present the case of a 39-year-old Bolivian woman with a history of seropositive rheumatoid arthritis of 12 years of evolution without extra-articular manifestations that develops a severe headache with vomiting. The diagnosis of rheumatoid meningitis was performed based on clinical history, blood count and biochemistry results, cerebrospinal fluid analysis and cranial magnetic resonance imaging findings. High-dose intravenous glucocorticoids were started, followed by rituximab. After treatment, a significant clinical improvement was observed and repeat magnetic resonance imaging scan confirmed an improvement of the meningeal lesions.

Extensive Intraspinal Hypermetabolism Caused by Neurobrucellosis Shown on 18F-FDG PET/CT

A 55-year-old man and a 52-year-old man presenting with neurological symptoms were referred for F-FDG PET/CT for the underlying malignancy. In both cases, extensive intraspinal hypermetabolism was observed in F-FDG PET/CT. The cerebrospinal fluid culture finally confirmed infection of Brucella. This report illustrates that neurobrucellosis may present as intraspinal hypermetabolism on F-FDG PET/CT, and thus it should be added to the differential diagnosis.

Primary leptomeningeal T-cell lymphoblastic lymphoma: a rare cause of chronic meningitis

Primary leptomeningeal lymphomatosis is a rare disease with only a few hundred cases reported. We present a patient with a relatively short history of 25 days of headache followed by diplopia who was found to have primary leptomeningeal T-cell lymphoma without evidence of systemic lymphoma. The patient responded well to chemotherapy along with intrathecal medication and cranial irradiation and returned to a completely normal state of health. Not all chronic meningitis is due to infection or self-limiting inflammatory causes. It is important to consider lymphoma as a differential even in the absence of constitutional features such as loss of weight, appetite, night sweats, lymphadenopathy or hepatosplenomegaly. T-cell lymphoma with only Central Nervous system (CNS) involvement is a rare cause of chronic meningitis, which is eminently amenable to treatment and is fatal if missed.

Meningeal Relapse of Nodular Lymphocyte Predominant Hodgkin Lymphoma Transformed to T-Cell/Histiocyte-Rich Large B-Cell Lymphoma: A Case Report

Central nervous system involvement in Hodgkin lymphoma is extremely rare, especially in nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), which usually carries a favorable prognosis. Here we report a case of a young patient with NLPHL, who developed a progressive and fatal neurological deterioration requiring a very extensive work-up including two biopsies to obtain the diagnosis of T-cell/histiocyte-rich large B-cell lymphoma like transformation. This report, which includes post-mortem analysis, highlights the correlations between clinical, radiological, and biological data but also the difficulties encountered in reaching the correct diagnosis.

Clinical presentation, treatment, and outcomes of patients with central nervous system involvement in extranodal natural killer/T-cell lymphoma

Extranodal natural killer (NK)/T-cell lymphoma (ENKTCL) is a rare type of Non-Hodgkin's lymphoma which rarely metastasizes to the central nervous system (CNS). Ten of 60 patients (16.7%) with ENKTCL followed at Memorial Sloan Kettering Cancer Center (MSKCC) were diagnosed with CNS involvement between 1995 and 2016. Eight patients had systemic disease at the time of CNS diagnosis; one patient never developed systemic disease and another was in remission at the time of CNS relapse. Median overall survival was 3.8 months; at time of this report 9 patients have died and one who underwent autologous stem cell transplant (ASCT) is alive 27 months after CNS diagnosis. Five patients achieved a complete response in the CNS; one is still alive, one died of systemic disease, and three died of infection. CNS ENKTCL portends a grim prognosis, with no standard treatment. Prospective study on ASCT and immunotherapy in CNS ENKTCL is warranted.

Primary dural lymphoma mimicking meningioma: a clinical and surgical case report

Introduction: Primary central nervous system lymphoma and its subtype, primary dural lymphoma, are types of non-Hodgkin's lymphoma that only occur in the central nervous system without any dissemination. They are extremely rare cases of extra nodal lymphomas accounting for 1--5% of intracranial tumors. Case report: We present a patient diagnosed with primary dural lymphoma in right frontal brain region who underwent surgical resection. Histopathological analysis revealed diffuse B-type large cell non-Hodgkin lymphoma. Patient underwent four cycles of R-CHOP and intrathecal methotrexate protocol. Six months postoperative, no signs of newly onset infiltration were present. Discussion: Primary dural lymphoma most likely presents with unusual radiological signs, which can easily be mistaken for meningioma, the main differential diagnosis. A thorough immunological, histopathological and clinical patients profile should be conducted in order to establish the certainty of diagnosis. Although there are few treatment options: surgery, radiotherapy or chemotherapy, there is no established treatment protocol.

Secondary central nervous system lymphoma surrounding a region injured by subarachnoid hemorrhage and subsequent aneurysmal clipping

The present case study describes a rare case of secondary central nervous system (CNS) lymphoma that infiltrated the dura and leptomeninges around the area injured by subarachnoid hemorrhage and subsequent aneurysmal clipping. Invasion of the CNS was observed by computed tomography as slurred fissures of the right parietal lobe adjacent to the surgery area. Subdural and subarachnoid enhancement overlapping the area injured by past surgical procedures was observed by contrast-enhanced magnetic resonance imaging. Surgical resection revealed B-cell lymphoma infiltrating the dura and leptomeninges surrounding the post-hemorrhagic area. The patient was subsequently diagnosed with systemic lymphoma and bone marrow invasion, and multiple lymph node swelling. To the best of our knowledge, this is the first report of malignant lymphoma involving the CNS overlapping a previously injured area.

Neuroimaging in Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare aggressive high-grade type of extranodal lymphoma. PCNSL can have a variable imaging appearance and can mimic other brain disorders such as encephalitis, demyelination, and stroke. In addition to PCNSL, the CNS can be secondarily involved by systemic lymphoma. Computed tomography and conventional MRI are the initial imaging modalities to evaluate these lesions. Recently, however, advanced MRI techniques are more often used in an effort to narrow the differential diagnosis and potentially inform diagnostic and therapeutic decisions.

Case of Primary Leptomeningeal Lymphoma Presenting with Papilloedema and Characteristics of Pseudotumor Syndrome

The authors describe an immunocompetent, 50-year-old man who complained of a daily transient blurring of his vision with bilateral papilloedema. His visual acuity was 20/20 OU, and the blind spot was enlarged bilaterally. There was intracranial hypertension, but imaging for systemic and brain tumours were negative. These findings suggested a diagnosis of the pseudotumor syndrome. However, MRI showed leptomeningeal enhancement, and acetazolamide successfully resolved his visual symptoms and papilloedema. Cytology and flow cytometry of the CSF led to the final diagnosis of primary leptomeningeal lymphoma (PLML). Clinicians need to be aware that a case of PLML may be misdiagnosed as peudotumor cerebri.

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.

Management of central nervous system involvement in chronic lymphocytic leukaemia: a retrospective cohort of 30 patients

Central nervous system involvement (CNSi) is a rare and poorly reported complication of chronic lymphocytic leukaemia (CLL). Establishing cause and effect between the CLL and the neurological symptoms remains challenging. We have analysed a retrospective cohort of 30 CLL patients with CNSi, documented by lymphocytic infiltration either by flow cytometry of the cerebrospinal fluid (CSF; n = 29) or CNS biopsy (n = 1). Neurological symptoms were heterogeneous. At the time of CNSi, less than half of the patients had a progressive CLL and 20 had never been treated for CLL. Initial treatment with fludarabine-based immuno-chemotherapy, with or without intra-CSF therapy, led to durable response in eight out of nine untreated patients. In contrast, 50% patients receiving various prior treatments needed additional therapy within a median of 4 months (1-16). Ibrutinib led to complete response in 4/4 heavily pre-treated patients. From CNSi, 5-year overall survival was 72% and 48% for treatment-naïve and previously treated patients respectively (P = 0·06); 5-year progression-free survival (PFS) was 43% and 0% (P = 0·125). 17p deletion was significantly associated with poor PFS (P = 0·006). CNSi may be the only sign of progression of CLL and should be considered an initiation criterion of systemic treatment. Prognosis seemed to be related to CLL characteristics rather than to CNSi itself.

Accuracy of flow cytometry and cytomorphology for the diagnosis of meningeal involvement in lymphoid neoplasms: A systematic review

Central nervous system (CNS) involvement by lymphoid neoplasms is a relatively infrequent event that demands accurate identification. The purpose of this article is to review studies comparing diagnostic accuracy of flow cytometry (FCM) and cytomorphology (CM) for meningeal involvement from lymphoid neoplasms. Primary publications from the last 26 years were identified searching MedLine, Scopus, and Web of Science and systematically scanning bibliographies of identified articles. Only studies reporting complete results were included. We assessed study quality using the QUADAS-2 tool. For each study, we extracted informations regarding study population, technical details about sample preparation, data analysis, and results. Twenty-seven studies were included. A great heterogeneity regarding study populations and analytical procedures was observed among studies. Percentages of samples giving a positive result with both FCM and CM range from 0.3% to 42.9% among studies, whereas double negative samples go from 0% to 96.3%. Samples with positive FCM but negative CM are reported by 89% (24/27) of the studies with rates ranging from 3.5% to 61.5% of total specimens. On the contrary, samples with positive CM and negative FCM are found in 48% (13/27) of the studies with percentages ranging from 0.5% to 10%. Despite all the differences observed among studies, almost all of them state that employing flow cytometry along with conventional cytology increases the number of positive CSF samples for lymphoma involvement, although a few cases remain in whom only morphology can correctly identify malignant cells. Diagn. Cytopathol. 2016;44:841-856. © 2016 Wiley Periodicals, Inc.

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.