Diagnosis of leptomeningeal disease in diffuse large B-cell lymphomas of the central nervous system by flow cytometry and cytopathology

Liquid biopsy for improving diagnosis and monitoring of CNS lymphomas: A RANO review

BACKGROUND

The utility of liquid biopsies is well documented in several extracranial and intracranial (brain/leptomeningeal metastases, gliomas) tumors.

METHODS

The RANO (Response Assessment in Neuro-Oncology) group has set up a multidisciplinary Task Force to critically review the role of blood and cerebrospinal fluid (CSF)-liquid biopsy in CNS lymphomas, with a main focus on primary central nervous system lymphomas (PCNSL).

RESULTS

Several clinical applications are suggested: diagnosis of PCNSL in critical settings (elderly or frail patients, deep locations, and steroid responsiveness), definition of minimal residual disease, early indication of tumor response or relapse following treatments, and prediction of outcome.

CONCLUSIONS

Thus far, no clinically validated circulating biomarkers for managing both primary and secondary CNS lymphomas exist. There is need of standardization of biofluid collection, choice of analytes, and type of technique to perform the molecular analysis. The various assays should be evaluated through well-organized central testing within clinical trials.

Intrathecal IgM synthesis as a diagnostic marker in patients with suspected CNS lymphoma

For CNS lymphomas (CNSL), there is a high need for minimally invasive and easily obtainable diagnostic markers. Intrathecal IgM synthesis can easily be determined in routine CSF diagnostics. The aim of this study was to systematically investigate the diagnostic potential of intrathecal IgM synthesis in primary and secondary CNSL (PCNSL and SCNSL). In this retrospective study, patients with a biopsy-proven diagnosis of PCNSL or SCNSL were compared with patients with other neurological diseases in whom CNSL was initially the primary radiological differential diagnosis based on MRI. Sensitivity and specificity of intrathecal IgM synthesis were calculated using receiver operating characteristic curves. Seventy patients with CNSL were included (49 PCNSL and 21 SCNSL) and compared to 70 control patients. The sensitivity and specificity for the diagnosis of CNSL were 49% and 87%, respectively, for the entire patient population and 66% and 91% after selection for cases with tumor access to the CSF system and isolated intrathecal IgM synthesis. In cases with MRI-based radiological suspicion of CNSL, intrathecal IgM synthesis has good specificity but limited sensitivity. Because of its low-threshold availability, analysis of intrathecal IgM synthesis has the potential to lead to higher diagnostic accuracy, especially in resource-limited settings, and deserves further study.

Molecular Analysis of Liquid Vitreous Biopsy Reveals Occult Lymphoma Following Cytology-Negative Biopsies of the Brain and Vitreous

PURPOSE

Primary central nervous system lymphoma (PCNSL) is a rare but deadly malignancy that principally affects adults in the fifth and sixth decades of life. Despite diagnostic advances in analyses of cerebral spinal fluid and neuroimaging, definitive diagnosis of PCNSL requires primary brain tissue biopsy. While small neurosurgical biopsy volumes are pursued to minimize removal of normal brain tissue, the spatial margins to precisely biopsy pathologic tissue are narrow and can result in missed diagnoses. Furthermore, prior steroid treatment can significantly reduce tumor burden increasing the likelihood of a non-diagnostic biopsy.

METHODS

A retrospective case report from a tertiary referral center using a combination of neuroradiological studies, sterotactic tissue biopsy, and molecular testing for genome mutations.

RESULTS

A 72-year-old woman with strong suspicion for PCNSL clinically and radiologically, but cerebral spinal fluid and primary brain tissue biopsy were negative for tumor. However, vitreous liquid biopsy molecular testing for a MYD88 mutation as well as B-cell clonality (IGH/IGK rearrangement) were positive, indicating the presence of secondary vitreoretinal lymphoma from PCNSL. Only after autopsy of her brain was histopathological and immunohistochemical evidence of PCNSL confirmed.

CONCLUSION

This case illustrates the unique contribution of liquid biopsy neuropathology-oriented molecular testing in a challenging case with high clinical suspicion of PCNSL in which gold-standard diagnostic testing failed to yield a diagnosis.

European survey on neurosurgical management of primary central nervous system lymphomas and preoperative corticosteroid therapy

Introduction

Preoperative corticosteroid therapy (CST) is common in primary central nervous system lymphoma (PCNSL) and may complicate histopathological diagnosis. There is an ongoing debate on the best management after preoperative CST.

Research question

We aimed to survey how different European neurosurgical units treat PCNSL patients after preoperative CST.

Methods

An English-language survey consisting of 21 questions addressing the management of patients with suspected PCNSL and preoperative CST was sent to European hospitals. The survey also included three clinical cases to assess the decision-making process in a clinical setting.

Results

The survey was completed by 74 European hospitals. There was no clear consensus on how to treat a patient with PCNSL after CST. Accordingly, 24.3% responded that they would generally defer surgery regardless of a possible radiological response, 47.3% would defer surgery only if there is regression in preoperative MRI and the remaining 28.4% would defer surgery only if the tumor had completely vanished. Furthermore, there were distinct discrepancies in responses of neurosurgical units regarding their general management approach and their case-based decision in the three example cases. The results of our survey also showed regional differences and differences in treatment decisions between high-, intermediate- and low-volume centers.

Discussion and conclusion

There was no clear consensus on how to treat patients with suspected PCNSL and preoperative CST. Furthermore, most centers also showed inconsistencies in their responses regarding their general approach as well as individual patient treatment. More high-quality evidence-based recommendations are needed to improve consensus and thus patient care.

Clinical applications of circulating tumor DNA in central nervous system lymphoma

Detection and characterization of circulating tumor DNA (ctDNA) in body fluids have the potential to revolutionize management of patients with lymphoma. Minimal access to malignant DNA through a simple blood draw or lumbar puncture is particularly appealing for CNS lymphomas (CNSL), which cannot be easily or repeatedly sampled without invasive surgeries. Profiling of ctDNA provides a real-time snapshot of the genetic composition in patients with CNSL and enables ultrasensitive quantification of lymphoma burden at any given time point during the course of the disease. Here, we broadly review technical challenges of ctDNA identification in CNSL, recent advances of innovative liquid biopsy technologies, potential clinical applications of ctDNA and how it may improve CNSL risk stratification, outcome prediction, and monitoring of measurable residual disease. Finally, we discuss clinical trials and scenarios in which ctDNA could be implemented to guide risk-adapted and personalized treatment decisions.

Clinicopathological analysis and specific discriminating markers of interleukin detection in cerebrospinal fluid with primary central nervous system lymphoma: results from a retrospective study

Primary central nervous system lymphoma (PCNSL) is special extranodal malignant non-Hodgkin lymphomas. This study analyzed clinical features and prognostic factors of PCNSL and evaluated the difference of interleukin (IL) concentrations in cerebrospinal fluid (CSF) between PCNSL and systemic non-Hodgkin lymphoma (sNHL). Patients consecutive newly diagnosed with PCNSL were recruited, the demographic and clinicopathological data were retrospectively analyzed, and the potential prognostic factors for overall survival (OS) were identified with survival analysis. 27 patients with PCNSL and 21 patients with sNHL collected CSF IL-5, IL-6, and IL-10 concentrations at diagnosis. The difference in interleukin (IL) concentrations in two diseases was analyzed to evaluate the value of IL concentrations. A total of 64 patients with PCNSL were enrolled, the median age was 54.50 years (range 16-85 years); male: female ratio was 1.91. Headache was the most common complaint symptom involved in 42.19% (27/64) of patients. Diffuse large B-cell lymphoma (DLBCL) accounted for 89.06% (57/64) of patients; other uncommon types accounted for 3.13% (2/64). In prognostic analysis, multiple lesions and Ki67 ≥ 75% expression exhibited a worse prognosis(P = 0.041), and patients with autologous hematopoietic stem cell transplantation (auto-HSCT) treatment presented superior OS (P < 0.05). In multivariate analysis, BCL2 expression was revealed as an unfavorable prognostic marker, and auto-HSCT was revealed as a favorable prognostic marker. CSF IL-10 concentration in patients with PCNSL was significantly higher than sNHL (P = 0.000) and excluded other histopathology of NHL; IL-10 value was still significantly different between DLBCL of PCNSL and sDLBCL (P = 0.003). In ROC curve analysis, the cutoff value of IL-10 was 0.43 pg/mL for the diagnosis value of PCNSL, sensitivity was 96.3%, specificity was 66.67%, and AUC was 0.84 (0.71-0.96). Although IL-6 concentration did not differ in the two groups, IL-10/IL-6 ratio was meaningful, with a cutoff value of 0.21, sensitivity of 81.48%, specificity of 80.95%, and AUC of 0.83 (0.71-0.95). This study highlights the characteristics of patients with PCNSL, potential prognostic makers also have been explained. CSF interleukin (IL) concentrations revealed IL-10 levels, and IL-10/IL-6 ratio may represent a useful biomarker in the differential diagnosis of PCNSL and sNHL.

Combining MYD88 L265P mutation detection and clonality determination on CSF cellular and cell-free DNA improves diagnosis of primary CNS lymphoma

Diagnosis of primary central nervous system lymphoma (PCNSL) is challenging, and although brain biopsy remains the gold standard, cerebrospinal fluid (CSF) constitutes a less invasive source of lymphomatous biomarkers. In a retrospective cohort of 54 PCNSL cases tested at diagnosis or relapse, we evaluated the contribution of immunoglobulin heavy chain (IGH) gene clonality and MYD88 L265P detection on both CSF cell pellets and supernatants, in comparison with cytology, flow cytometry, interleukin (IL)-10 and IL-6 quantification. Clonality assessment included a new assay to detect partial IGH-DJ rearrangements. Clonal IGH rearrangements and/or MYD88 L265P mutation were detected in 27 (50%) cell pellets and 24 (44%) supernatant cell-free (cf) DNA. Combining analyses on both compartments, 36 (66%) cases had at least one detectable molecular marker, present only in cfDNA for 9 (16%) of them. While cytology and flow cytometry were positive in only 7 (13.0%) and 9 (17.3%) cases respectively, high IL-10 levels were observed in 36 (66.7%) cases. Overall, taking into account molecular and cytokine results, 46/54 (85%) cases had at least one lymphomatous biomarker detectable in the CSF. These results show that this combination of biomarkers evaluated on both cell pellet and supernatant CSF fractions improves significantly the biological diagnosis of PCNSL.

Circulating Tumor DNA Profiling for Detection, Risk Stratification, and Classification of Brain Lymphomas

PURPOSE

Clinical outcomes of patients with CNS lymphomas (CNSLs) are remarkably heterogeneous, yet identification of patients at high risk for treatment failure is challenging. Furthermore, CNSL diagnosis often remains unconfirmed because of contraindications for invasive stereotactic biopsies. Therefore, improved biomarkers are needed to better stratify patients into risk groups, predict treatment response, and noninvasively identify CNSL.

PATIENTS AND METHODS

We explored the value of circulating tumor DNA (ctDNA) for early outcome prediction, measurable residual disease monitoring, and surgery-free CNSL identification by applying ultrasensitive targeted next-generation sequencing to a total of 306 tumor, plasma, and CSF specimens from 136 patients with brain cancers, including 92 patients with CNSL.

RESULTS

Before therapy, ctDNA was detectable in 78% of plasma and 100% of CSF samples. Patients with positive ctDNA in pretreatment plasma had significantly shorter progression-free survival (PFS, P < .0001, log-rank test) and overall survival (OS, P = .0001, log-rank test). In multivariate analyses including established clinical and radiographic risk factors, pretreatment plasma ctDNA concentrations were independently prognostic of clinical outcomes (PFS HR, 1.4; 95% CI, 1.0 to 1.9; P = .03; OS HR, 1.6; 95% CI, 1.1 to 2.2; P = .006). Moreover, measurable residual disease detection by plasma ctDNA monitoring during treatment identified patients with particularly poor prognosis following curative-intent immunochemotherapy (PFS, P = .0002; OS, P = .004, log-rank test). Finally, we developed a proof-of-principle machine learning approach for biopsy-free CNSL identification from ctDNA, showing sensitivities of 59% (CSF) and 25% (plasma) with high positive predictive value.

CONCLUSION

We demonstrate robust and ultrasensitive detection of ctDNA at various disease milestones in CNSL. Our findings highlight the role of ctDNA as a noninvasive biomarker and its potential value for personalized risk stratification and treatment guidance in patients with CNSL.

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Primary meningeal central nervous system lymphoma: A case report and literature review

RATIONALE

Primary central nervous system lymphoma (PCNSL) is a rare extranodal non-Hodgkin lymphoma, and isolated meningeal PCNSL, without evidence of parenchymal involvement, is even less common, occurring in only 10% to 15% of cases.

PATIENT CONCERNS

A 65-years-old female presented to our hospital with progressive lower extremity motor dysfunction and blurred vision. The initial neurological examination revealed decreased muscle strength in both lower extremities and sensory dysfunction of lower extremities, saddle area, and buttocks. Brain magnetic resonance imaging showed no abnormalities. Lumbar enhanced magnetic resonance imaging showed T11 to L3 horizontal meningeal enhancement. Cerebrospinal fluid (CSF) cytology revealed lymphoma cells. Immunohistochemistry and flow cytometry of the CSF were performed as auxiliary methods to establish the diagnosis of lymphoma.

DIAGNOSES

The patient was diagnosed primary meningeal central nervous system lymphoma.

INTERVENTIONS

During hospitalization, the patient was treated with 2 courses of high-dose intrathecal methotrexate and rituximab combined with intrathecal chemotherapy and supportive treatment.

OUTCOMES

After 2 years of follow-up, the patient was able to walk and take care of herself.

LESSONS

Cases of PCNSL involving only the meninges are rare. Multimodal analysis of the CSF comprises an important component of the diagnostic work-up for patients with primary meningeal central nervous system lymphoma.

Progress of radiological‑pathological workflows in the differential diagnosis between primary central nervous system lymphoma and high‑grade glioma (Review)

Primary central nervous system lymphoma (PCNSL) and high‑grade glioma (HGG) are distinct entities of the CNS with completely distinct treatments. The treatment of PCNSL is chemotherapy‑based, while surgery is the first choice for HGG. However, the clinical features of the two entities often overlap, and a clear pathological diagnosis is important for subsequent management, especially for the management of PCNSL. Stereotactic biopsy is recognized as one of the minimally invasive alternatives for evaluating the involvement of the CNS. However, in the case of limited tissue materials, the differential diagnosis between the two entities is still difficult. In addition, some patients are too ill to tolerate a needle biopsy. Therefore, combining imaging, histopathology and laboratory examinations is essential in order to make a clear diagnosis as soon as possible. The present study reviews the progress of comparative research on both imaging and laboratory tests based on the pathophysiological changes of the two entities, and proposes an integrative and optimized diagnostic process, with the purpose of building a better understanding for neurologists, hematologists, radiologists and pathologists.

Intratumor heterogeneity and T cell exhaustion in primary CNS lymphoma

Background

Primary central nervous system lymphoma (PCNSL) is a rare lymphoma of the central nervous system, usually of diffuse large B cell phenotype. Stereotactic biopsy followed by histopathology is the diagnostic standard. However, limited material is available from CNS biopsies, thus impeding an in-depth characterization of PCNSL.

Methods

We performed flow cytometry, single-cell RNA sequencing, and B cell receptor sequencing of PCNSL cells released from biopsy material, blood, and cerebrospinal fluid (CSF), and spatial transcriptomics of biopsy samples.

Results

PCNSL-released cells were predominantly activated CD19⁺CD20⁺CD38⁺CD27⁺ B cells. In single-cell RNA sequencing, PCNSL cells were transcriptionally heterogeneous, forming multiple malignant B cell clusters. Hyperexpanded B cell clones were shared between biopsy- and CSF- but not blood-derived cells. T cells in the tumor microenvironment upregulated immune checkpoint molecules, thereby recognizing immune evasion signals from PCNSL cells. Spatial transcriptomics revealed heterogeneous spatial organization of malignant B cell clusters, mirroring their transcriptional heterogeneity across patients, and pronounced expression of T cell exhaustion markers, co-localizing with a highly malignant B cell cluster.

Conclusions

Malignant B cells in PCNSL show transcriptional and spatial intratumor heterogeneity. T cell exhaustion is frequent in the PCNSL microenvironment, co-localizes with malignant cells, and highlights the potential of personalized treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01110-1.

Accuracy and safety of 101 consecutives neurosurgical procedures for newly diagnosed central nervous system lymphomas: a single-institution experience

INTRODUCTION

Brain surgery is required to ascertain the diagnosis of central nervous system lymphoma. We assessed the diagnostic yield and safety of the surgical procedures, the predictors of postoperative morbidity, and of overall survival.

METHODS

Observational single-institution retrospective cohort study (1992-2020) of 101 consecutive adult patients who underwent stereotactic biopsy, open biopsy, or resection for a newly diagnosed central nervous system lymphoma.

RESULTS

The diagnostic yield was 100% despite preoperative steroid administration in 48/101 cases (47.5%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.006) was an independent predictor of a new postoperative focal neurological deficit (7/101 cases, 6.9%). A previous history of hematological malignancy (p = 0.049), age 65 years or more (p = 0.031), and new postoperative neurological deficit (p < 0.001) were independent predictors of a Karnofsky Performance Status score decrease 20 points or more postoperatively (13/101 cases, 12.9%). A previous history of hematological malignancy (p = 0.034), and preoperative Karnofsky Performance Status score less than 70 (p = 0.024) were independent predictors of postoperative hemorrhage (13/101 cases, 12.9%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.019), and a previous history of hematological malignancy (p = 0.014) were independent predictors of death during hospital stay (8/101 cases, 7.9%). In the 82 immunocompetent patients harboring a primary central nervous system lymphoma, age 65 years or more (p = 0.044), and time to hematological treatment more than 21 days (p = 0.008), were independent predictors of a shorter overall survival. A dedicated hematological treatment (p < 0.001) was an independent predictor of a longer overall survival.

CONCLUSION

Brain biopsy is feasible with low morbidity for central nervous system lymphomas. Postoperatively, patients should be promptly referred for hematological treatment initiation.

Clinical Features, Diagnosis, and Treatment of Primary Intraventricular Lymphoma: Insights From a Monocentric Case Series

Objective

Primary ventricular lymphoma (PVL) is an extremely rare and commonly misdiagnosed disease. Previous studies were predominantly case reports, and literature regarding the diagnosis and treatment of PVL is limited. Therefore, this study aimed to evaluate the characteristics of patients with PVL.

Methods

The data of patients with pathologically confirmed PVL were assessed. Epidemiological data, imaging findings, surgery, pathological results, and prognosis were retrospectively analyzed. A systematic review of relevant literature was also conducted.

Results

A total of eight patients with PVL were identified. The main symptom was increased intracranial pressure. Radiographically, five patients had single lesion and three had multiple lesions; typical findings on magnetic resonance imaging included hypointensity on T1- and T2-weighted imaging, adjacent brain edema, and homogeneous enhancement on contrast-enhanced T1-weighted images. Preoperatively, six cases were misdiagnosed and two cases did not get a definite diagnosis. Craniotomy was performed on all patients, and four achieved gross total resection. Hydrocephalus was relieved after surgical resection in four patients. Pathology revealed diffuse large B-cell lymphoma in all patients. Only one patient had a severe complication. A total of three patients received concomitant adjuvant treatment, whereas five patients refused any adjuvant therapy. At the time of follow-up, the median survival time of patients was 15 months.

Conclusion

Primary ventricular lymphoma mainly presented with symptoms of increased intracranial pressure and had several imaging characteristics for the diagnosis, but the condition still tends to be misdiagnosed. Surgical resection is a feasible treatment for patients with isolated nodules, especially those with acute obstructive hydrocephalus.

An Update on Neurosurgical Management of Primary CNS Lymphoma in Immunocompetent Patients

Primary central nervous system lymphomas (PCNSL) are rare CNS tumors that harbor a conspicuously longer diagnostic delay compared to other malignant brain tumors. The gold standard for diagnosis is stereotactic biopsy to acquire tissue for histopathological analysis and therefore neurosurgery plays a central role when reducing the diagnostic period is mandated. However, histopathological diagnosis could be complicated if the patient was preoperatively exposed to corticosteroids. Besides the histopathological result, diagnosis of a PCNSL also requires full diagnostic workup to exclude cerebral metastatic disease of a systemic lymphoma. Most reviews of PCNSL discuss recent advancements in systemic treatment options from an (neuro-)oncologic viewpoint, whereas our intention was to discuss the optimization of the diagnostic period and therefore describe current standards of imaging, summarizing the diagnostic workup, discussing the surgical workup and future diagnostic prospects as well as the influence of preoperative corticosteroid therapy to reduce the diagnostic delay of PCNSL patients.

Value of cerebrospinal fluid white cell count and protein level in predicting leptomeningeal involvement by systemic aggressive B-cell lymphoma

INTRODUCTION

Diagnostic cerebrospinal fluid (CSF) analysis for patients with newly diagnosed aggressive B-cell lymphoma at risk of secondary central nervous system involvement typically includes multiparametric flow cytometry (MFC), cytology (CC), white cell count (WCC) and total protein. The strength of relationships between MFC results and the remaining variables has been disputed in small studies. We explored these relationships in a large homogeneous cohort of patient samples, aiming to establish the relationship between WCC and protein level and MFC results.

METHODS

Adult patients with aggressive B-cell lymphoma at risk of CNS involvement who underwent staging CSF analysis by MFC were identified retrospectively from institutional electronic records between October 2011 and December 2020.

RESULTS

Three hundred and seventy eight samples, including 45 (11.9%) MFC+ samples, were analysed. The relative sensitivity of CC for MFC positivity was 0.38, with PPV of 0.68. Significantly higher median WCC (p < .001) and protein levels (p = .011) were seen in MFC+ vs. MFC- samples. MFC + CC+ (vs. MFC + CC- samples) demonstrated higher median neoplastic events and neoplastic cell concentration. WCC ≥36 × 10⁶ /L and protein ≥1.12 g/L cut-off values demonstrated the highest PPVs for MFC positivity (0.67 and 0.88, respectively).

CONCLUSIONS

Statistically significant associations exist between elevated WCC and protein and MFC positivity, and selected WCC and protein cut-off values have PPVs comparable to that of cytological assessment. Whilst routine WCC and protein analysis may be unnecessary, WCC/protein values above these levels could be regarded as reasonable evidence of CSF involvement in the appropriate setting.

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.

Liquid Biopsy and Other Non-Invasive Diagnostic Measures in PCNSL

Simple Summary

Primary central nervous system lymphoma (PCNSL) is an uncommon disease accounting for around 3% of primary CNS tumors. PCNSL exhibits aggressive clinical behavior and has an overall poor prognosis. The clinical presentation is variable, and there are no specific symptoms. Despite progress in radiographic neuroimaging, stereotactic brain biopsy remains obligatory for definitive diagnosis. Advanced standard diagnostics, including CSF cytology and flow cytometry, have limited sensitivity. Accordingly, there is an urgent need to improve the diagnostic tools for PCNSL, including novel non-invasive procedures. The aim of this review is to present and discuss modern methods that have the potential to contribute standard clinical diagnostics within the next few years.

Abstract

Primary central nervous system lymphoma is a rare but highly aggressive form of non-Hodgkin lymphoma that remains confined to the CNS neuroaxis. The diagnosis of PCNSL requires a high level of suspicion as clinical presentation varies depending on the involved CNS areas. Neurological symptoms and MRI findings may mimic gliomas, demyelinating lesions, or infectious and granulomatous diseases. Almost all PCNSL patients undergo invasive surgical procedures for definite diagnosis. Stereotactic biopsy is still the gold standard in achieving a diagnostic accuracy of 73–97%. Both the potential procedural morbidity and mortality, as well as the time to definite histopathologic diagnosis resulting in delays of treatment initiation, have to be considered. On the contrary, minimally invasive procedures, such as MRI, CSF cytology, and flow cytometry, still have limited value due to inferior specificity and sensitivity. Hence, novel diagnostic approaches, including mutation analyses (MYD88) in circulating tumor DNA (ctDNA) and the determination of microRNAs (miR-21, miR-19b, and miR-92) as well as cytokine levels (IL10 and IL6) in blood, cerebrospinal fluid (CSF), and vitreous fluid (VRF), move into the focus of investigation to facilitate the diagnosis of PCNSL. In this review, we outline the most promising approaches that are currently under clinical consideration.

Cell-Block cytology in diagnosis of primary central nervous system lymphoma: A case report

INTRODUCTION

Primary Central Nervous System Lymphoma (PCNSL) remains a diagnostic challenge due to the variable clinical manifestations. Liquid biopsies, particularly those involving cell-free DNA (cfDNA) from plasma, are rapidly emerging as important and minimally invasive adjuncts to traditional biopsies. However, conventional pathology may be still essential to obtain a diagnosis.

PATIENT CONCERNS

A 56-year-old woman presented with a progressive headache, dizziness, blurred vision, and lower limbs weakness with dysesthesia. Atypical clinical and radiological presentations, previous empirical treatment in another hospital, together with the patient's refusal to stereotactic brain biopsy made it challenging to diagnose. Her status deteriorated continuously during hospitalization.

DIAGNOSIS

Lumber punctual was performed, and CSF cytological analysis revealed malignancy cells with a high nuclear-cytoplasmic ratio. However, these cells were too loose to perform immunohistochemical stains. Genetic aberrations detections with CSF and peripheral blood sample were also inconclusive. We made a "cell-block" using the sedimentary cells collected from CSF collected through multiple aspirations via an Omaya reservoir. We further performed cytopathological and immunohistochemical analysis using this "cell-block," which finally confirmed the diagnosis of diffuse large-B cell PCNSL.

INTERVENTIONS

Intracranial chemotherapy began afterwards (MTX 15 mg and dexamethasone 5 mg, twice per weeks).

OUTCOMES

Unfortunately, this patient was dead 2 weeks later due to severe myelosuppression and secondary septic shock.

CONCLUSION

We provided "cell-block" method, which collects cell components from large amount of CSF for cytology and immunohistochemical analysis. "Cell-block" cytology can be an alternative diagnostic method in diagnosis of PCNSL.

High Detection Rate of MYD88 Mutations in Cerebrospinal Fluid From Patients With CNS Lymphomas

PURPOSE

Biopsy is the gold standard for the diagnosis of primary CNS lymphoma (PCNSL). However, surgical biopsy has problems of morbidity related to hemorrhagic complications and false-negative findings, so safer and more reliable diagnostic methods are required. The aim of this study is to detect the MYD88 mutation, an important driver mutation, in the cerebrospinal fluid (CSF) of patients with CNS lymphoma.

PATIENTS AND METHODS

Twenty-six patients with CNS lymphoma (20 primary CNS lymphoma and six CNS relapse from systemic lymphoma) were studied. We extracted cell-free DNA (cfDNA) from CSF by lumbar puncture. cfDNA was extracted from 1 mL of CSF, and Sanger sequencing and droplet digital polymerase chain reaction (ddPCR) were performed. Furthermore, we performed DNA sequencing of MYD88 in 21 cases with available surgically obtained formalin-fixed paraffin-embedded (FFPE) tissue and compared the results.

RESULTS

The median cfDNA amount extracted from 1 mL CSF was 219 ng/mL (25th to 75th percentile, 129 to 333 ng/mL). MYD88 mutations were detected from CSF in 76.9% (20 of 26 cases), and L265P in exon 5 was the most frequent mutation in 19 out of 20 (95.0%) cases. S219C in exon 3 was detected in one case. In four patients, MYD88 mutation was confirmed by ddPCR but not by Sanger sequencing. In all 21 cases with sufficient FFPE tissue for DNA analysis, the detection of MYD88 mutation from cfDNA was consistent with those of tumor-derived DNA from FFPE tissue.

CONCLUSION

This pilot study provided evidence that the somatic driver mutation MYD88 can be reliably detected by combination of Sanger sequencing and ddPCR in the cfDNA taken from 1 mL of CSF in patients with CNS lymphomas.

Potential Diagnosis of Vitreoretinal Lymphoma by Detection of MYD88 Mutation in Aqueous Humor With Ultrasensitive Droplet Digital Polymerase Chain Reaction

Importance

The diagnostic workup of patients suspected of having vitreoretinal lymphoma (VRL) is primarily based on vitreous fluid analysis, including the recently emerging myeloid differentiation primary response gene 88 (MYD88) mutation analysis. Aqueous humor paracentesis is a relatively less invasive and safer procedure than taking vitreous fluid specimens, and aqueous humor-based MYD88 mutation analysis would provide an additional liquid biopsy tool to diagnose and monitor patients with VRL.

Objective

To investigate whether the detection of MYD88 L265P by highly sensitive droplet digital polymerase chain reaction (ddPCR) is feasible in the vitreous fluid and aqueous humor of patients with VRL.

Design, Setting, and Participants

This cohort study includes aqueous humor and vitreous fluid samples from patients with VRL who were treated at the University Medical Center Utrecht, in Utrecht, the Netherlands, from August 2005 to August 2017. Ocular fluids were randomized and masked before MYD88 L265P analysis, which was performed using an in-house validated ddPCR platform. Patients with uveitis were included as a comparison group.

Main Outcomes and Measures

The presence of MYD88 L265P mutation detected by ddPCR in AH and VF.

Results

The study included 96 samples from 63 individuals, including 23 patients with VRL (of whom 10 were female and 13 male, with a mean [SD] age of 72 [7.3] years) and 40 individuals with uveitis (of whom 23 were female and 17 male, with a mean [SD] age of 58 [20.9] years). In 17 of 23 patients with VRL (74%), MYD88 L265P was detected; it was not detected in any of the patients with uveitis. It was detectable in both vitreous fluid and aqueous humor samples. In the paired samples, the mutation was detected in 8 of 9 aqueous humor samples (89%) of the MYD88 L265P-positive vitreous fluid samples. In vitreous fluid, the MYD88 ddPCR test showed a sensitivity of 75% (95% CI, 50%-92%) and a positive predictive value of 100%; in aqueous humor, sensitivity was 67% (95% CI, 42%-92%), and positive predictive value was 100%. Specificity was 100% in both fluids. After treatment, the mutation was no longer detectable in any ocular fluids.

Conclusions and Relevance

The high concordance between aqueous humor and vitreous fluid samples suggests that use of the easily accessible aqueous humor is nearly as informative as vitreous fluid in the identification of key somatic mutations in patients with VRL. This approach may provide an additional minimally invasive tool for accurate diagnosis, detection of recurrence, and monitoring of treatment.

Flow cytometry shows added value in diagnosing lymphoma in brain biopsies

Background

To assess the sensitivity, specificity and turnaround time of flow cytometric analysis on brain biopsies compared to histology plus immunohistochemistry analysis in tumors with clinical suspicion of lymphoma.

Methods

All brain biopsies performed between 2010 and 2015 at our institution and analyzed by both immunohistochemistry and flow cytometry were included in this retrospective study. Immunohistochemistry was considered the gold standard.

Results

In a total of 77 biopsies from 71 patients, 49 lymphomas were diagnosed by immunohistochemistry, flow cytometry results were concordant in 71 biopsies (92.2%). We found a specificity and sensitivity of flow cytometry of 100% and 87.8%, respectively. The time between the biopsy and reporting the result (turnaround time) was significantly shorter for flow cytometry, compared to immunohistochemistry (median: 1 vs. 5 days).

Conclusions

Flow cytometry has a high specificity and can confirm the diagnosis of a lymphoma significantly faster than immunohistochemistry. This allows for rapid initiation of treatment in this highly aggressive tumor. However, since its sensitivity is less than 100%, we recommend to perform histology plus immunohistochemistry in parallel to flow cytometry. © 2018 The Authors. Cytometry Part B: Clinical Cytometry published by Wiley Periodicals, Inc. on behalf of International Clinical Cytometry Society

Primary CNS Lymphomas: Challenges in Diagnosis and Monitoring

Primary Central Nervous System Lymphoma (PCNSL) is a rare neoplasm that can involve brain, eye, leptomeninges, and rarely spinal cord. PCNSL lesions most typically enhance homogeneously on T1-weighted magnetic resonance imaging (MRI) and appear T2-hypointense, but high variability in MRI features is commonly encountered. Neurological symptoms and MRI findings may mimic high grade gliomas (HGGs), tumefactive demyelinating lesions (TDLs), or infectious and granulomatous diseases. Advanced MRI techniques (MR diffusion, spectroscopy, and perfusion) and metabolic imaging, such as Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) or amino acid PET (usually employing methionine), may be useful in distinguishing these different entities and monitoring the disease course. Moreover, emerging data suggest a role for cerebrospinal fluid (CSF) markers in predicting prognosis and response to treatments. In this review, we will address the challenges in PCNSL diagnosis, assessment of response to treatments, and evaluation of potential neurotoxicity related to chemotherapy and radiotherapy.

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.

Challenges and prospects in the diagnosis and treatment of primary central nervous system lymphoma

Introduction: Primary central nervous system lymphoma (PCNSL) retains peculiar biological and clinical characteristics and a worse prognosis with respect to other comparable lymphomas. The need for high doses of chemotherapy to achieve valid drug concentrations in cerebral tissues and/or radiotherapy results in severe treatment-related toxicities, mainly neurologic, which are frequently as disabling as the disease itself.Areas covered: Several emerging combined therapies are addressed that focus on treating PCNSL. The prognosis has improved in the last years but several questions remain unanswered and the research of more effective therapies goes on. Information and data were obtained from direct authors' experience and a PubMed search of recent peer-reviewed original articles, review articles, and clinical guidelines.Expert commentary: The substantial progress observed in PCNSL has to be ascribed to a carefully combination of standard chemotherapeutic drugs. High-dose methotrexate-based polychemotherapy followed by mainteinance therapy offers one of the best chances to control the disease. Major issues that deserve many efforts by researchers are the definition of optimal consolidation treatment and a shared management of specific conditions such as elderly population and intra-ocular localization.

CSF and clinical data are useful in differentiating CNS inflammatory demyelinating disease from CNS lymphoma

Background:

It is often difficult to diagnose central nervous system (CNS) inflammatory demyelinating diseases (IDDs) because they are similar to CNS lymphoma and glioma.

Objective:

To evaluate whether cerebrospinal fluid (CSF) analysis can differentiate CNS IDDs from CNS lymphoma and glioma.

Methods:

We measured CSF cell counts; concentrations of proteins, glucose, interleukin (IL)-6, IL-10, soluble IL-2 receptor (sIL-2R), and myelin basic protein; and IgG index in patients with multiple sclerosis (MS, n = 64), neuromyelitis optica spectrum disorder (NMOSD, n = 35), tumefactive demyelinating lesion (TDL, n = 17), CNS lymphoma ( n = 12), or glioma ( n = 10). We detected diagnostic markers using logistic regression and receiver operating characteristic (ROC) analyses.

Results:

Median CSF IL-10 and sIL-2R levels were higher in CNS lymphoma patients than in MS, NMOSD, or TDL patients. Logistic regression revealed that CSF sIL-2R levels predicted CNS lymphoma. In the ROC analysis of CSF sIL-2R levels, the area under the curve was 0.867, and the sensitivity and specificity were 83.3% and 90.0%, respectively.

Conclusion:

CSF sIL-2R levels can be used to differentiate CNS lymphoma from CNS IDDs. Further studies may identify other applications of CSF as a diagnostic biomarker.

Case-based review: primary central nervous system lymphoma

Primary CNS lymphoma (PCNSL) is a rare diffuse large B-cell lymphoma originating within the central nervous system. The overall incidence of PCNSL is rising, particularly in the elderly population. Immunosuppression is a strong risk factor, but most patients with this tumor are apparently immunocompetent. Diagnosis of PCNSL can be challenging. Non-invasive or minimally invasive tests such as ophthalmological evaluation and spinal fluid analysis may be useful, but the majority of patients require tumor biopsy for definitive diagnosis. Our knowledge concerning optimum treatment of PCNSL is fragmentary due to paucity of adequately sized trials. Most patients are now initially treated with high-dose-methotrexate-based chemotherapy alone, as the addition of whole-brain radiotherapy at standard doses has not been shown to increase survival and does increase the risk of neurological toxicity. Ongoing trials are addressing issues such as the roles of reduced-dose radiotherapy, the addition of the CD20 antibody rituximab to chemotherapy, high-dose chemotherapy followed by autologous stem cell transplantation, and maintenance therapy in the primary management of PCNSL.

Minimally Invasive Diagnosis of Secondary Intracranial Lymphoma

Diffuse large B cell lymphomas (DLBCL) are an aggressive group of non-Hodgkin lymphoid malignancies which have diverse presentation and can have high mortality. Central nervous system relapse is rare but has poor survival. We present the diagnosis of primary mandibular DLBCL and a unique minimally invasive diagnosis of secondary intracranial recurrence. This case highlights the manifold radiological contributions to the diagnosis and management of lymphoma.

Brain stereotactic biopsy flow cytometry for central nervous system lymphoma characterization: advantages and pitfalls

BACKGROUND

Brain stereotactic biopsy (SB) followed by conventional histopathology and immunohistochemistry (IHC) is the gold standard approach for primary central nervous system lymphoma (PCNSL) diagnosis. Flow cytometry (FCM) characterization of fine-needle aspiration cytology and core needle biopsies are increasingly utilized to diagnose lymphomas however, no biological data have been published on FCM characterization of fresh single cell suspension from PCNSL SB. The aim of this study was to establish the feasibility and utility of FCM for the diagnosis and characterization of brain lymphomas from a tissue samples obtained by a single SB disaggregation.

METHODS

Twenty-nine patients with a magnetic resonance suggestive for PCNSL entered the study. A median of 6 SB were performed for each patient. A cell suspension generated from manual tissue disaggregation of a single, unfixed, brain SB, was characterized by FCM. The FCM versus standard approach was prospectively compared.

RESULTS

FCM and IHC showed an high degree of agreement (89 %) in brain lymphoma identification. By FCM, 16 out of 18 PCNSL were identified within 2 h from biopsy. All were of B cell type, with a heterogeneous CD20 mean fluorescence intensity (MFI), CD10 positive in 3 cases (19 %) with surface Ig light chain restriction documented in 11 cases (69 %). No false positive lymphomas cases were observed. Up to 38 % of the brain leukocyte population consisted of CD8 reactive T cells, in contrast with the CD4 positive lymphocytes of the peripheral blood samples (P < 0.001). By histopathology, 18 B-PCNSL, only one CD10 positive (5 %), 1 primitive neuroectodermal tumor (PNET) and 10 gliomas were diagnosed. A median of 6 days was required for IHC diagnosis.

CONCLUSION

Complementary to histopathology FCM can contribute to a better characterization of PCNSL, although necrosis and previous steroid treatment can represent a pitfall of this approach. A single brain SB is a valid source for accurate FCM characterization of both lymphoma and reactive lymphocyte population, routinely applicable for antigen intensity quantification and consistently documenting an active mechanism of reactive CD8 T-lymphocytes migration in brain lymphomas. Moreover, FCM confirmed to be more sensitive than IHC for the identification of selected markers.

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.

Osteopontin in cerebrospinal fluid as diagnostic biomarker for central nervous system lymphoma

Central nervous system lymphoma (CNSL) is diagnostically challenging. The identification of reliable and easy to measure biomarkers is desirable to facilitate diagnosis. Here, we evaluated the value of cerebrospinal fluid (CSF) osteopontin (OPN) as a diagnostic biomarker for CNSL. OPN concentrations in CSF from 37 patients with CNSL (29 with primary CNSL and 8 with secondary CNS involvement of systemic lymphoma) and 36 controls [6 patients with inflammatory CNS disease other than multiple sclerosis (MS), 8 with MS, 9 with glioblastoma (GBM) and 13 healthy controls] were determined using an enzyme-linked immunosorbent assay. Non-parametric tests and receiver operating characteristic (ROC) curves were performed for determination of diagnostic accuracy. Median CSF OPN level in all CNSL patients was 620 ng/mL and higher than in patients with inflammatory CNS disease (356 ng/mL); P < .05, MS (163 ng/mL); P < .01, GBM (41 ng/mL); P < .01, or healthy controls (319 ng/mL); P < .01. The area under the ROC curve was 0.865 [95 % confidence interval (CI) 0.745-0.985] for differentiating CNSL and patients with inflammatory CNS disease; 0.956 (95 % CI 0.898-1.000) for CNSL and MS patients; 0.988 (95 % CI 0.964-1.000) for CNSL and GBM patients, and 0.915 (95 % CI 0.834-0.996) for CNSL patients and healthy controls. In multivariate analysis, high CSF OPN level was associated with shorter progression-free (HR 1.61, 95 % CI 1.13-2.31; P = .009) and overall survival (HR 1.52, 95 % CI 1.04-2.21; P = .029). CSF OPN is a potential biomarker in CNSL.

Absence of Lymphatic Vessels in PCNSL May Contribute to Confinement of Tumor Cells to the Central Nervous System

Primary central nervous system (CNS) lymphoma (PCNSL) is a mature lymphoma of the diffuse large B-cell lymphoma (DLBCL) type confined to the CNS. Despite cytomorphological similarities between PCNSL and systemic DLBCL, molecular differences between both entities have been identified. The exclusively topographical restriction of PCNSL to the CNS is an unexplained mystery. To address the question of whether the unique lymphatic drainage system of the CNS, which differs from that of other organs, may play a role for this peculiar behavior, we investigated a series of 20 PCNSLs for the presence of lymphatic vessels by immunohistochemistry for Lyve-1, podoplanin, and Prox-1 expression. All PCNSLs lacked lymphatic vessels and, in this regard, were similar to 20 glioblastoma multiforme samples. In contrast to these tumors, all of which were located in the deep brain parenchyma, dural and meningeal DLBCL harbored lymphatic vessels that expressed Lyve-1 (3/8 tumors), podoplanin (5/8 tumors), and Prox-1 (5/8 tumors) in areas where the tumors had invaded the fibrous tissue of the dura. These data indicate that local topographical characteristics of the specific lymphatic drainage system may contribute to confinement of the tumor cells in PCNSL and malignant gliomas.

Lymphomatosis cerebri: a rare form of primary central nervous system lymphoma. Analysis of 7 cases and systematic review of the literature

BACKGROUND

Primary central nervous system lymphomas may present as diffuse, nonenhancing infiltrative lesions. This rare variant is termed lymphomatosis cerebri (LC). We did a systematic review and analysis of the literature, adding our own cases, to better characterize LC in order to improve early diagnosis and treatment.

METHODS

PubMed, ISI Web of Knowledge, and hospital databases were reviewed. Information was extracted regarding demographic, clinical, histological, cerebrospinal fluid (CSF), neuroimaging, and treatment variables. The impact of single parameters on overall survival (OS) was determined by applying univariate and multivariate analyses.

RESULTS

Forty-two patients were included (median age: 58 y; range: 28-80 y). At consultation, 52% of patients had a poor KPS. The most common presenting symptom was cognitive decline (59.5%). Imaging studies showed supratentorial and infratentorial infiltration in 55% of patients and bilateral hemispheric involvement in 95%. CSF pleocytosis was present in 51.5% of the patients. Median time to diagnosis was 4.5 (range: 1-30) months, and the diagnosis was not established until autopsy for 33% of patients. The median OS was 2.95 (range: 0.33-56) months; however, those patients who received methotrexate had a median OS of 13.8 (range: 0.7-56) months. Analysis identified KPS ≥ 70 (HR: 0.32; 95% CI: 0.114-0.894; P = .03) and treatment with methotrexate (HR: 0.19; 95% CI: 0.041-0.886; P = .034) as independent favorable prognostic factors, whereas T-cell lymphoma was independently related with a worse outcome (HR: 6.62; 95% CI: 1.317-33.316; P = .022).

CONCLUSIONS

LC is a misdiagnosed entity associated with considerable diagnostic delay. MRI evidence of bilateral hemispheric involvement and CSF pleocytosis should be alerts for this diagnosis. Treatment with methotrexate-based chemotherapy must be considered, especially for patients with good KPS.

Cytomorphologic and Flow Cytometric Analysis of Cerebrospinal Fluid with T-Cell Lymphoma Involvement: A Retrospective Study of Rare Cases

OBJECTIVE

To compare the efficacy of conventional cytomorphologic analysis and flow cytometry (FC) in the diagnosis of T-cell lymphoma in the cerebrospinal fluid (CSF).

STUDY DESIGN

We performed a retrospective review of CSF samples from 2002 to 2012 that showed involvement of a T-cell lymphoma, either by cytomorphologic analysis and/or FC. Patients' demographics, clinical history and follow-up were assessed.

RESULTS

Thirty-nine CSF samples were identified from 9 patients. A definitive diagnosis of T-cell lymphoma involvement was made by cytomorphologic analysis and FC in 6 (15.4%) and 39 (100.0%) specimens, respectively. In specimens with definitive cytopathologic diagnoses, the cytomorphologic features included increased cellularity, a monotonous lymphoid population and large, atypical lymphoid cells. Considering cytomorphologic features only, 9 specimens demonstrated atypical lymphocytes not fulfilling the criteria for malignancy, and 24 specimens were negative for malignancy.

CONCLUSIONS

CSF with T-cell lymphoma involvement may yield paucicellular or acellular specimens depending on the volume of the CSF, the time interval between specimen collection and specimen processing and the application of preservative to CSF. The rate of detection of T-cell lymphoma in the CSF by FC is unequivocally higher than by cytomorphologic analysis. Careful attention to clinical history is crucial, as FC testing may be tailored to evaluate for T-cell lymphoproliferative disorders in limited samples.

On chip analysis of CNS lymphoma in cerebrospinal fluid

Molecular profiling of central nervous system lymphomas in cerebrospinal fluid (CSF) samples can be challenging due to the paucicellular and limited nature of the samples. Presented herein is a microfluidic platform for complete CSF lymphoid cell analysis, including single cell capture in sub-nanoliter traps, and molecular and chemotherapeutic response profiling via on-chip imaging, all in less than one hour. The system can detect scant lymphoma cells and quantitate their kappa/lambda immunoglobulin light chain restriction patterns. The approach can be further customized for measurement of additional biomarkers, such as those for differential diagnosis of lymphoma subtypes or for prognosis, as well as for imaging exposure to experimental drugs.

Modern cerebrospinal fluid analyses for the diagnosis of diffuse large B-cell lymphoma of the CNS

CNS lymphomas represent rare and aggressive variants of extranodal non-Hodgkin's lymphomas, which may present with diverse neurological symptoms and are often diagnostically challenging. Primary CNS lymphomas develop within the CNS and characteristically involve the brain, leptomeninges, eyes and, in rare cases, spinal cord. Secondary CNS lymphomas are characterized by expansion of systemic lymphomas to the CNS. Multimodal investigation of cerebrospinal fluid (CSF) comprises an important component of the diagnostic work-up for patients with suspected CNS lymphomas. Cytopathological examination of the CSF is still regarded as the 'gold standard' for the diagnosis of leptomeningeal malignant disease. However, cytopathology has only a low sensitivity in detecting leptomeningeal lymphoma involvement. Modern technologies including proteochemical and immunophenotypic studies by flow cytometry, and molecular genetic analyses of CSF may increase sensitivity and specificity, therefore, facilitating the diagnosis of CNS lymphomas. This review gives an overview and discussion of the current aspects of CSF analyses in CNS lymphomas.

Diagnostic utility of cerebrospinal fluid flow cytometry in patients with and without prior hematologic malignancy

Flow cytometry (FCM) is an adjunct study to routine analysis of cerebrospinal fluid (CSF) to investigate for involvement by a hematologic malignancy. However, in our experience, FCM only infrequently detects abnormalities in CSF. To help optimize resources without forfeiting clinically important data, we sought to determine evidence-based indications and criteria for performing FCM on CSF. FCM results of 316 consecutive CSF specimens were retrospectively reviewed and correlated with clinical history, total nucleated cell (TNC) counts, and results of concurrent cytologic review. Of 255 samples adequate for analysis, 54% were from patients with a prior history of hematologic malignancy, of which 12% (17 cases) were abnormal by FCM. Corresponding TNC counts among samples with abnormal FCM ranged from 0-1050 cells/µL, and only 44% showed abnormal morphology on concurrent cytology. Of the remaining 46% of samples from patients with no known history of hematologic malignancy who had CSF sampling for neurological indications, only one (1%) was abnormal by FCM. This specimen had an elevated TNC count (39 cells/µL) but lacked clearly abnormal findings on concurrent cytology. These results support the use of CSF FCM only in patients with a history of hematologic malignancy or, in the absence of such a history, in samples showing pleocytosis. If these criteria were applied to the current cohort using a TNC count cut-off of >5 cells/µL, 23% of samples would have been deferred from testing, resulting in decreased cost, improved efficiency, and reduction in the need for unnecessary testing without a negative impact on clinical care.

Leptomeningeal involvement in B-cell chronic lymphocytic leukemia: a case report and review of the literature

BACKGROUND

Central nervous system involvement is considered a rare complication of chronic lymphocytic leukemia, and so there is the risk of being overlooked.

CASE PRESENTATION

We report a case of central nervous system involvement in a 75-year-old mulatto woman with chronic lymphocytic leukemia after 5 years of follow-up and a literature review on the subject. The clinical course, treatment and outcome are described. A systematic, meticulous and comprehensive analysis of existing publications regarding chronic lymphocytic leukemia with central nervous system involvement was performed.

CONCLUSION

We concluded that central nervous system involvement of chronic lymphocytic leukemia is probably not associated with any evident risk factors. Diagnostic approach differs by institutions but often includes imaging, morphology and flow cytometry. Resolution of central nervous system symptoms can usually be accomplished with intrathecal chemotherapy or irradiation followed by systemic treatment. The recognition of this entity by clinicians could lead to early detection and treatment, resulting in better outcomes in this rare complication.

MicroRNAs as Potential Biomarkers for Diagnosing Cancers of Central Nervous System: a Meta-analysis

Recent studies have shown abnormal microRNA (miRNA) expression levels in the central nervous system (CNS) of cancer patients, suggesting that miRNAs may serve as promising biomarkers for cancers of CNS. However, other studies have arrived at conflicting results. Therefore, this meta-analysis aims to systematically measure the potential diagnostic value of miRNAs for CNS cancers. Electronic databases as well as other sources were searched until to April 12, 2014 for relevant articles. Data from different studies were pooled using the random-effects model. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative LR (NLR), diagnostic odds ratio (DOR), together with the summary receiver operator characteristic (SROC) curve, and area under the SROC curve (AUC) value were used to estimate overall diagnostic performance. Twenty-three studies from 6 articles were included in the current meta-analysis with a total of 299 CNS cancer patients and 418 controls. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.85 (95% CI, 0.80-0.89), 0.83 (95% CI, 0.76-0.88), 5.1 (95% CI, 3.4-7.5), 0.18 (95% CI, 0.12-0.26), 28 (95% CI, 14-58), and 0.91 (95% CI, 0.88-0.93), respectively. Subgroup analyses showed that cerebrospinal fluid (CSF)-based miRNAs assays yielded more accurate results and seemed to be more sensitive in diagnosing of primary central nervous system lymphoma (PCNSL). In conclusion, miRNAs may be suitable for serving as noninvasive biomarkers for CNS cancers detection. However, further validation based on a larger sample of patients and controls is still required.

Factors associated with survival among patients with AIDS-related primary central nervous system lymphoma

OBJECTIVE

AIDS-related primary central nervous system lymphoma (AR-PCNSL) has a poor prognosis. Improved understanding of specific patient, infectious, diagnostic, and treatment-related factors that affect overall survival (OS) is required to improve outcomes.

DESIGN

Population-based registry linkage study.

METHODS

Adult cases from the San Francisco AIDS registry (1990-2000) were matched with the California Cancer Registry (1985-2002) to ascertain AR-PCNSL data. Survival time was assessed through 31 December 2007. Risk factors and temporal trends for death were measured using two-sided Kaplan-Meier and Cox analyses.

RESULTS

Two hundred and seven AR-PCNSL patients were identified: 68% were white, 20% Hispanic, 10% African-American, and 2% Asian. Nineteen percent of patients had central nervous system (CNS) opportunistic infections diagnosed prior to AR-PCNSL. Fifty-seven percent of patients received radiation and/or chemotherapy and 12% used HAART prior to or within 30 days of AR-PCNSL diagnosis. One hundred and ninety-nine patients died (34 deaths/100 person-years). In adjusted analysis, prior CNS opportunistic infection diagnosis increased risk of death (hazard ratio 1.9, P = 0.0006) whereas radiation and/or chemotherapy decreased risk (hazard ratio 0.6, P < 0.0001). AR-PCNSL diagnosis 1999-2002 had a lower mortality risk (hazard ratio = 0.4, P = 0.02) compared to 1990-1995. African-Americans had an increased risk of death compared to whites or Asians (hazard ratio = 2.0, P = 0.007).

CONCLUSION

OS among AR-PCNSL patients improved over time but remains poor, especially among African-Americans. Prospective evaluation of curative therapy in AR-PCNSL is urgently needed. Accurate diagnosis of CNS mass lesions in patients with AIDS is required and for those with AR-PCNSL, antiretroviral therapy with concomitant AR-PCNSL therapy, and antimicrobial supportive care may improve OS.

Primary lymphoma of the central nervous system--a diagnostic challenge

Primary lymphoma of the central nervous system is a distinct diffuse large B-cell lymphoma confined to the nervous system. Whereas classical cases can be classified easily, differential diagnosis can be a challenge in particular in patients who had received treatment prior to biopsy. In the differential diagnosis, other tumours and inflammatory diseases of autoimmune and infectious aetiology need to be considered.

Diagnosis and treatment of primary CNS lymphoma

Primary CNS lymphoma (PCNSL) is a rare lymphoma that is confined to the CNS, with low tendency for systemic dissemination and a relatively aggressive course. Outcome in patients with PCNSL is often poor. Owing to its low incidence, current knowledge about optimal treatment of PCNSL is fragmentary. Chemotherapy regimens based on high-dose methotrexate are currently standard treatment for all patients with PCNSL who can tolerate such drugs. Whole-brain radiotherapy alone can lead to remission in up to 90% of patients, but often results in poor long-term disease control when given alone, and in delayed neurotoxicity when given after high-dose methotrexate. In this Review, we describe current approaches to diagnosis and treatment of PCNSL, and discuss novel therapeutic approaches that are currently in development, such as the use of rituximab and high-dose chemotherapy followed by autologous stem-cell transplantation. The possible use of intrathecal and intraventricular chemotherapy, optimal salvage treatment, and specific treatment approaches in elderly, paediatric and immunocompromised patients, are also considered.

Detection of occult cerebrospinal fluid involvement during maintenance therapy identifies a group of children with acute lymphoblastic leukemia at high risk for relapse

We aimed at assessing the clinical significance of the levels of acute lymphoblastic leukemia (ALL) cells in samples of cerebrospinal fluid (CSF) during therapy. We studied 990 CSF samples from 108 patients, at the time of diagnosis (108) and at each time of intrathecal therapy (882). The proportions of leukemic cells in CSF samples were assessed by flow cytometry (FCM). Patients with central nervous system (CNS) involvement at diagnosis (FCM+) showed predominantly a T-ALL, and higher percentages of known negative prognostic factors: high risk group, higher white blood cell counts, normal karyotype, and the BCR-ABL fusion gene. No differences in relapse free survival (RFS) and overall survival (OS) were observed between FCM+ versus FCM- at diagnosis. Patients with CNS involvement during therapy showed significantly older age, and higher frequencies of T-cell leukemia. We found a significantly higher RFS in patients with FCM+ during therapy. The detection of subclinical CNS disease by FCM during maintenance was associated with significantly lower 3-years RFS and 3-years OS. A sensitive methodology like FCM can be applied for a close follow-up of the levels of ALL in CFS samples, and may identify a group of patients at high risk for relapse.

Diagnostic strategies to investigate cerebrospinal fluid involvement in haematological malignancies

Central nervous system (CNS) involvement is a fatal complication of certain haematological malignancies with an incidence as high as 25% in specific leukaemia/lymphoma subtypes. It is often accompanied by 'occult' cerebrospinal fluid (CSF) involvement at diagnosis, which is frequently missed by conventional cytology examination. Unfortunately, a diagnostic gold standard is yet unavailable since CSF morphology may be negative for malignant cells in up to 45% of patients with suspected meningeal involvement. New technologies such as flow cytometry, molecular genetics and newer biomarkers may improve sensitivity and specificity facilitating the diagnosis of CNS involvement as well as effective prophylaxis and successful treatment.

Pathogenesis and management of primary CNS lymphoma

Primary CNS lymphoma (PCNSL), a rare variant of extranodal non-Hodgkin's lymphoma, may cause various neurological symptoms and signs. The best therapeutic strategy is still a matter of debate. High-dose methotrexate (HD-MTX) is the most active compound and should be used as the backbone for any chemotherapy applied. Several other chemotherapeutic drugs have been assessed in combination with HD-MTX, but no standard has yet been defined. Whole-brain radiotherapy is active against PCNSL, but typically does not confer long-lasting remission and is associated with significant neurotoxicity in many patients. The recently published G-PCNSL-SG1 trial has shown that consolidating whole-brain radiotherapy after HD-MTX-based chemotherapy does not prolong overall survival and may therefore be deferred. Combined systemic and intraventricular polychemotherapy, or high-dose chemotherapy followed by stem cell transplantation may offer cures to younger patients. Improving treatment regimens without adding significant (neuro-)toxicity should be the focus of ongoing and future studies.