Primary central nervous system lymphoma: a clinicopathological study of 75 cases

Primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a diffuse large B cell lymphoma in which the brain, spinal cord, leptomeninges and/or eyes are exclusive sites of disease. Pathophysiology is incompletely understood, although a central role seems to comprise immunoglobulins binding to self-proteins expressed in the central nervous system (CNS) and alterations of genes involved in B cell receptor, Toll-like receptor and NF-κB signalling. Other factors such as T cells, macrophages or microglia, endothelial cells, chemokines, and interleukins, probably also have important roles. Clinical presentation varies depending on the involved regions of the CNS. Standard of care includes methotrexate-based polychemotherapy followed by age-tailored thiotepa-based conditioned autologous stem cell transplantation and, in patients unsuitable for such treatment, consolidation with whole-brain radiotherapy or single-drug maintenance. Personalized treatment, primary radiotherapy and only supportive care should be considered in unfit, frail patients. Despite available treatments, 15-25% of patients do not respond to chemotherapy and 25-50% relapse after initial response. Relapse rates are higher in older patients, although the prognosis of patients experiencing relapse is poor independent of age. Further research is needed to identify diagnostic biomarkers, treatments with higher efficacy and less neurotoxicity, strategies to improve the penetration of drugs into the CNS, and roles of other therapies such as immunotherapies and adoptive cell therapies.

Amide proton transfer MRI differentiates between progressive multifocal leukoencephalopathy and malignant brain tumors: a pilot study

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nerve system caused by the John Cunningham virus. On MRI, PML may sometimes appear similar to primary central nervous system lymphoma (PCNSL) and glioblastoma multiforme (GBM). The purpose of this pilot study was to evaluate the potential of amide proton transfer (APT) imaging for differentiating PML from PCNSL and GBM.

METHODS

Patients with PML (n = 4; two men; mean age 52.3 ± 6.1 years), PCNSL (n = 7; four women; mean age 74.4 ± 5.8 years), or GBM (n = 11; 6 men; mean age 65.0 ± 15.2 years) who underwent APT-CEST MRI between January 2021 and September 2022 were retrospectively evaluated. Magnetization transfer ratio asymmetry (MTR_asym) values were measured on APT imaging using a region of interest within the lesion. Receiver operating characteristics curve analysis was used to determine diagnostic cutoffs for MTR_asym.

RESULTS

The mean MTR_asym values were 0.005 ± 0.005 in the PML group, 0.025 ± 0.005 in the PCNSL group, and 0.025 ± 0.009 in the GBM group. There were significant differences in MTR_asym between PML and PCNSL (P = 0.023), and between PML and GBM (P = 0.015). For differentiating PML from PCNSL, an MTR_asym threshold of 0.0165 gave diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of 100% (all). For differentiating PML from GBM, an MTR_asym threshold of 0.015 gave diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 90.9%, 80.0%, and 100%, respectively.

CONCLUSION

MTR_asym values obtained from APT imaging allowed patients with PML to be clearly discriminated from patients with PCNSL or GBM.

Prognostic significance of pretreatment red blood cell distribution width in primary diffuse large B-cell lymphoma of the central nervous system for 3P medical approaches in multiple cohorts

Background/aims

Predicting the clinical outcomes of primary diffuse large B-cell lymphoma of the central nervous system (PCNS-DLBCL) to methotrexate-based combination immunochemotherapy treatment in advance and therefore administering the tailored treatment to the individual is consistent with the principle of predictive, preventive, and personalized medicine (PPPM/3PM). The red blood cell distribution width (RDW) has been reported to be associated with the clinical outcomes of multiple cancer. However, its prognostic role in PCNS-DLBCL is yet to be evaluated. Therefore, we aimed to effectively stratify PCNS-DLBCL patients with different prognosis in advance and early identify the patients who were appropriate to methotrexate-based combination immunochemotherapy based on the pretreatment level of RDW and a clinical prognostic model.

Methods

A prospective-retrospective, multi-cohort study was conducted from 2010 to 2020. We evaluated RDW in 179 patients (retrospective discovery cohorts of Huashan Center and Renji Center and prospective validation cohort of Cancer Center) with PCNS-DLBCL treated with methotrexate-based combination immunochemotherapy. A generalized additive model with locally estimated scatterplot smoothing was used to identify the relationship between pretreatment RDW levels and clinical outcomes. The high vs low risk of RDW combined with MSKCC score was determined by a minimal P-value approach. The clinical outcomes in different groups were then investigated.

Results

The pretreatment RDW showed a U-shaped relationship with the risk of overall survival (OS, P = 0.047). The low RDW (< 12.6) and high RDW (> 13.4) groups showed significantly worse OS (P < 0.05) and progression-free survival (PFS; P < 0.05) than the median group (13.4 > RDW > 12.6) in the discovery and validation cohort, respectively. RDW could predict the clinical outcomes successfully. In the discovery cohort, RDW achieved the area under the receiver operating characteristic curve (AUC) of 0.9206 in predicting the clinical outcomes, and the predictive value (AUC = 0.7177) of RDW was verified in the validation cohort. In addition, RDW combined with MSKCC predictive model can distinguish clinical outcomes with the AUC of 0.8348 for OS and 0.8125 for PFS. Compared with the RDW and MSKCC prognosis variables, the RDW combined with MSKCC scores better identified a subgroup of patients with favorable long-term survival in the validation cohort (P < 0.001). RDW combined MSKCC score remained to be independently associated with clinical outcomes by multivariable analysis.

Conclusions

Based on the pretreatment RDW and MSKCC scores, a novel predictive tool was established to stratify PCNS-DLBCL patients with different prognosis effectively. The predictive model developed accordingly is promising to judge the response of PCNS-DLBCL to methotrexate-based combination immunochemotherapy treatment. Thus, hematologists and oncologists could tailor and adjust therapeutic modalities by monitoring RDW in a prospective rather than the reactive manner, which could save medical expenditures and is a key concept in 3PM. In brief, RDW combined with MSKCC model could serve as an important tool for predicting the response to different treatment and the clinical outcomes for PCNS-DLBCL, which could conform with the principles of predictive, preventive, and personalized medicine.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-022-00290-5.

Recent Progress on Primary Central Nervous System Lymphoma-From Bench to Bedside

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extra-nodal lymphoma. The high relapse rate of PCNSL remains a major challenge to the hematologists, even though patients exhibit high sensitivity to the methotrexate-based chemotherapeutic regimens. Recently, the advent of Bruton's tyrosine kinase inhibitor (BTKi) and CAR T treatment has made more treatment options available to a proportion of patients. However, whether BTKi monotherapy should be given alone or in combination with conventional chemotherapy is still a clinical question. The status of CAR T therapy for PCNSLs also needs to be elucidated. In this review, we summarized the latest progress on the epidemiology, pathology, clinical manifestation, diagnosis, and treatment options for PCNSLs.

A case report of secondary neurolymphomatosis showing selective nerve infiltration and massive lumbar plexus enlargement

Background

Neurolymphomatosis (NL) is a rare manifestation of malignant lymphoma that shows selective infiltration to the peripheral nervous system primarily or secondarily. We report a patient with secondary NL caused by germinal center B-cell (GCB)-type diffuse large B-cell lymphoma (DLBCL) who showed selective infiltration of the lumbar plexus to the spinal cord and massive nerve enlargement resulting in severe pain.

Case presentation

A 72-year-old female exhibited asymmetric motor and sensory impairments and pain in the lower limbs that progressed for five months. Magnetic resonance imaging (MRI) showed an enlarged lumbar plexus, which continued to the cauda equina via the L3 and L4 spinal nerves. Her symptoms gradually worsened. Ten months after the onset of symptoms, the enlarged cauda equina filled the spinal canal space, and the spinal cord was swollen. A cauda equina biopsy was performed, and she was diagnosed with GCB-type DLBCL with CD10 positivity. The primary tumor was found in a mammary cyst. The autopsy study did not show apparent infiltration, except in the nervous system.

Conclusions

Although there are many neurologic phenotypes of malignant lymphoma, the association between the cytological characteristics of lymphoma and the neurological phenotypes is still unclear. Several reports of CD10-positive secondary NL are available, whereas peripheral or central nervous tissue origin lymphoma cases are mostly negative for CD10. CD10 staining may be useful for distinguishing primary NL from secondary NL. NL often has a strong organotropism for peripheral nervous tissue, which makes early diagnosis challenging.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02330-5.

Prognostic models in primary central nervous system lymphoma patients: A systematic review

Over the last decade, several prognostic models have been proposed for primary central nervous system lymphoma (PCNSL), but consensus on the optimal model for these patients is absent or lacking. This study aims to review available prognostic models for PCNSL and discuss their prognostic features. A comprehensive literature search performed in Pubmed/Embase identified ten studies with a variable number of analysed patients (range 32-3453), which proposed 12 prognostic models. Age and performance status were the most important prognostic factors in PCNSL and an integral part of the majority of the proposed models. However, there is no universally accepted prognostic model for PCNSL owning to a number of limitations such as a small number of patients, limited samples obtained for genetic analysis, retrospective nature of studies, single centre studies, and lack of validation. Future multicentre studies are necessary to determine the optimal prognostic model for PCNSL by combining different prognostic markers of significance.

Diagnosis, prognosis and treatment of primary central nervous system lymphoma in the elderly population (Review)

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal non-Hodgkin lymphoma that is unique and different from systemic diffuse large B-cell lymphomas. The median age at diagnosis of PCNSL is 65 years and its incidence is rising rapidly in the elderly population. A total of ≥20% of all patients with PCNSL are ≥80 years old. Notably, age has been identified as an independent poor prognostic factor for PCNSL. Elderly patients have an inferior prognosis to that of younger patients and are more severely affected by iatrogenic toxicity; therefore, elderly patients represent a unique and vulnerable treatment subgroup. The present review summarized the available literature to provide an improved understanding of the epidemiology, clinical characteristics, diagnosis, prognosis and management of PCNSL in the elderly population. Notably, the incidence of PCNSL in immunocompetent elderly patients, predominantly in men, is increasing. For the diagnosis of CNSL, imaging-guided stereotactic biopsy is considered the gold standard. When stereotactic biopsy is not possible or conclusive, certain biomarkers have been described that can help establish a diagnosis. PCNSL has a very poor prognosis in the elderly, even though several prognostic scoring systems exist and several prognostic markers have been reported in patients with PCNSL. Furthermore, the treatment of elderly patients remains challenging; it is unlikely that a novel agent could be used as a curative monotherapy; however, a combination of novel agents with polychemotherapy or its combination with other novel drugs may have therapeutic potential.

Epstein-Barr Virus-Positive Primary Central Nervous System Lymphoma in a 40-Year-Old Immunocompetent Patient

Epstein-Barr virus-positive (EBV+) primary central nervous system lymphoma (PCNSL) is a clinical entity rarely reported in young immunocompetent patients. Here, we present the case of a 40-year-old female with no history of immunosuppression or immunodeficiency, who presented with a ring-enhancing lesion in the right basal ganglia. The tumor generated significant vasogenic edema and mass effect, causing midline shift, symptoms of increased intracranial pressure, and rapidly progressive neurologic dysfunction. She underwent gross total resection of the tumor through a tubular retractor. Her tumor was of the diffuse large B cell lymphoma (DLBCL) subtype of PCNSL and was positive for EBV. No immunodeficiency or extracranial disease was identified. After adjuvant therapy with high-dose methotrexate, rituximab, and temozolomide, she remains disease-free two years after initial presentation. EBV+ PCNSL, although rare in young immunocompetent adults, poses unique clinical challenges and may require surgical intervention in the acute setting in some cases.

Clinicopathological features of primary central nervous system diffuse large B cell lymphoma: Experience from a Tertiary Center in North India

BACKGROUND

Primary central nervous system-diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare extra-nodal Non-Hodgkin lymphoma. There is relative paucity of literature on PCNSL from Indian subcontinent. We aimed to analyze the clinicopathological features of PCNSL and categorize them into germinal center B cell (GCB) and non-GCB subtypes to assess their prognostic significance in Indian context.

METHODS

All patients with histopathologically diagnosed PCNSLs at our center over a period of 6 years were recruited and classified into GCB and non-GCB using Han's algorithm (immunohistochemistry for CD10, BCL6 and MUM1). In situ hybridization (ISH) for Epstein-Barr virus (EBV)-encoded RNA was performed.

RESULTS

Eighty-six cases of PCNS-DLBCL were included with median age of 55 years. Majority of them were supratentorial in location (n = 62). All patients were immunocompetent. On immunohistochemical assessment, 69 (80.2%) were of NGCB subtype, 10 (11.6%) were of GCB subtype, and 7 (8.1%) were unclassified. Overall, MUM1, BCL-6, and CD10 expressions were seen in 69 (80.2%), 28 (32.6%), and 2 cases (2.3%), respectively. Four cases (4.6%) showed C-MYC expression. The median overall survival (OS) was 675 days. None of the factors (age, sex, location, immunomarkers, and GCB vs. NGCB phenotype) showed correlation with OS; however, BCL6 positive cases showed slight better OS (P > 0.05). All cases were negative for EBV-LMP1 on ISH.

CONCLUSION

The majority of the CNS DLBCL belongs to non-GCB phenotype and uniformly carry poor prognosis, irrespective of their phenotype. Individual markers, such as BCL-6, MUM1, or CD10, are unable to predict outcome in PCNS-DLBCL.

Immune Checkpoint Molecules in Primary Diffuse Large B-Cell Lymphoma of the Central Nervous System

Introduction:

Primary Diffuse Large B Cell Lymphoma of CNS (PCNSL) is a rare variant of Diffuse Large B Cell Lymphoma (DLBCL) and presents with an aggressive clinical course and usually resistant to commonly used therapy regimens. Recently, role of immune checkpoint molecules including PD-1 and PD-L1 confirmed in some solid tumors and lymphoma resulting tumor cells escape the immune system and help to survive and to spread. Inhibitors of PD-1 and PD-L1 have shown lasting responses in several solid and some hematological tumors, while limited studies evaluate checkpoint molecules on PCNSL.

Method:

In this study, we investigated PD-1 and PD-L1 expression by immunostaining on 71 patients with PCNSL and correlation with demographic data, location of the tumor, proliferation rate, cell of origin, and CD8 positive T cell infiltration in tumor microenvironment.

Results:

16 from71 showed PD-1 expression, while PD-L1 expression were 42/71. No association was determined between PD-1/PD-L1 expression and gender, cell of origin, and proliferation rate, but a highly significant difference was determined between the infiltration of CD8 positive T cells in two groups of PD-1/PD-L1 positive and negative.

Conclusion:

This study revealed expression of check point molecules in remarkable number of PCNSL which may open new therapeutic recommendations in this aggressive lymphoma type.

Rare Primary Central Nervous System Tumors in Adults: An Overview

Overall, tumors of primary central nervous system (CNS) are quite common in adults with an incidence rate close to 30 new cases/100,000 inhabitants per year. Significant clinical and biological advances have been accomplished in the most common adult primary CNS tumors (i.e., diffuse gliomas). However, most CNS tumor subtypes are rare with an incidence rate below the threshold defining rare disease of 6.0 new cases/100,000 inhabitants per year. Close to 150 entities of primary CNS tumors have now been identified by the novel integrated histomolecular classification published by the World Health Organization (WHO) and its updates by the c-IMPACT NOW consortium (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy). While these entities can be better classified into smaller groups either by their histomolecular features and/or by their location, assessing their treatment by clinical trials and improving the survival of patients remain challenging. Despite these tumors are rare, research, and advances remain slower compared to diffuse gliomas for instance. In some cases (i.e., ependymoma, medulloblastoma) the understanding is high because single or few driver mutations have been defined. The European Union has launched European Reference Networks (ERNs) dedicated to support advances on the clinical side of rare diseases including rare cancers. The ERN for rare solid adult tumors is termed EURACAN. Within EURACAN, Domain 10 brings together the European patient advocacy groups (ePAGs) and physicians dedicated to improving outcomes in rare primary CNS tumors and also aims at supporting research, care and teaching in the field. In this review, we discuss the relevant biological and clinical characteristics, clinical management of patients, and research directions for the following types of rare primary CNS tumors: medulloblastoma, pineal region tumors, glioneuronal and rare glial tumors, ependymal tumors, grade III meningioma and mesenchymal tumors, primary central nervous system lymphoma, germ cell tumors, spinal cord tumors and rare pituitary tumors.

Molecular profiling of primary central nervous system lymphomas - predictive and prognostic value?

PURPOSE OF REVIEW

Primary central nervous system lymphoma (PCNSL) is a rare but aggressive variant of non-Hodgkin lymphoma. The diagnostic gold standard remains the pathologic review of tumor tissue mainly collected though biopsies. The majority of PCNSL are diffuse large B cell lymphoma (DLBCL). Biopsies are invasive procedures, and there have been efforts to develop minimally invasive diagnostic testing using serum and cerebral spinal fluid. This article reviews multiple markers that could potentially serve as future diagnostic tools and predictors of treatment response.

RECENT FINDINGS

Many studies have attempted to classify DLBCL into different subtypes for prognostic purposes using methods such as immunohistochemistry. PCNSL often falls under the activated B-cell-like subgroup, and further genomic sequencing has identified alterations in genes within the B-cell receptor signaling axis at increased frequencies. Two such genes, MYD88 and CD79B, implicate the involvement of the NF-kB (nuclear factor kappa-light-chain enhancer of activated B cells) pathway, and targeted agents to this pathway are currently being used in the treatment of relapsed/refractory PCNSL.

SUMMARY

Although recent genomic profiling of PCNSL has increased the understanding of drivers in this disease and has also led to the introduction of targeted inhibitors, these markers have not yet been used for diagnostic and/or prognostic purposes. Further studies will need to evaluate if they hold great diagnostic potential.

Primary central nervous system lymphoma in China: a single-center retrospective analysis of 167 cases

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin's lymphoma and a limited number of cases have been reported from China. This study aimed to investigate the clinicopathological features of newly diagnosed PCNSLs from a single center in eastern China and to identify the potential prognostic factors for overall survival (OS) and progression-free survival (PFS). All consecutive patients with histopathologically diagnosed PCNSLs at our center between January 2003 and October 2017 were recruited. Demographic and clinicopathological data were collected and reviewed retrospectively. The potential risk factors for OS and PFS were identified using the log-rank test and Cox regression analysis. A total of 167 immunocompetent cases were enrolled. The median age was 58 years (range 17-96 years), and the male:female ratio was 3:2. Headache (n = 65; 39%) and cerebral hemisphere (n = 96; 57%) were the most common presenting complaint and location, respectively. Out of 167 cases, 150 cases were diffuse large B cell lymphomas. With a median follow-up of 25 months (range 1-152 ), the median OS and PFS were 37 months (95% CI, 25-49) and 17 months (95% CI, 13-20), respectively. Residual tumor after operation, chemotherapy without HD-MTX and palliative treatment was revealed as independent prognostic markers. Moreover, ECOG > 3, multifocal lesions, and palliative treatment were revealed as unfavorable independent prognostic markers for PFS. In conclusion, Chinese patients with PCNSL have distinct characteristics. Further studies are warranted to confirm the prognostic value of these factors and to optimize treatments for these patients.

Primary Intra-Axial Diffuse Large B-Cell Lymphoma in Immunocompetent Patients: Clinical Impact of Molecular Analysis and Histogenetic Evaluation

Primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) represents less than 1% of non-Hodgkin lymphomas and 2%-3% of brain tumors. Primary CNS DLBCL occurs sporadically in healthy patients. Tumor development and progression have been associated with reduced/absent expression of human leukocyte antigen class I and II proteins; increased expression of CXCR4, CXCL12, CXCR5, and CCR7; mutations of VH4/34, BCL6, MYC, and PAX5 genes; and rearrangement of immunoglobulin heavy and light chain genes. Generally, DLBCL is a single supratentorial lesion (60%-70%), and stereotactic biopsy and intraoperative examination are the main diagnostic methods. Distinctive histologic features are a diffuse growth pattern and angioinvasiveness. Most neoplastic cells resemble centroblasts and exhibit positive CD20, CD22, PAX5, CD79a, and MUM1 expression. The prognosis of primary CNS DLBCL is less favorable than that of nodal DLBCL, and DLBCL subtype, strong FOXP1 immunoreactivity, MYC and BCL2 overexpression, and BCL6 translocations are associated with poor prognosis.

The role of surgery in primary central nervous system lymphomas

ABSTRACT Background Primary central nervous system lymphomas (PCNSL) are infrequent. The traditional treatment of choice is chemotherapy. Complete resections have generally not been recommended, because of the risk of permanent central nervous system deficits with no proven improvement in survival. The aim of the current study was to compare survival among patients with PCNSL who underwent biopsy versus surgical resection. Methods A retrospective study was conducted on 50 patients with a confirmed diagnosis of PCNSL treated at our center from January 1994 to July 2015. Results Patients in the resection group exhibited significantly longer median survival time, relative to the biopsy group, surviving a median 31 months versus 14.5 months; p = 0.016. Conclusions In our series, patients who had surgical resection of their tumor survived a median 16.5 months longer than patients who underwent biopsy alone.

Immunohistochemical profile and prognostic significance in primary central nervous system lymphoma: Analysis of 89 cases

The majority of primary central nervous system lymphomas (PCNSLs) are diffuse large B cell lymphoma, characterized by poor prognosis. In the present study, the expression of cluster of differentiation (CD)10, B cell lymphoma (BCL)-6, multiple myeloma-1 (MUM-1), BCL-2, CD138 and Ki-67 was analyzed by immunohistochemistry in 89 Chinese PCNSL cases, and the potential prognostic significance was evaluated. CD10, BCL-6, MUM-1, BCL-2 and CD138 were positive in 16.9 (15/89), 51.7 (46/89), 92.1 (82/89), 73.3 (63/86) and 0% (0/65) of all cases, respectively. According to the Hans algorithm, 71 patients (79.8%) were classified into the non-germinal center B cell-like (non-GCB) group, indicating a post-germinal center origin of PCNSL. The median follow-up time of 73 patients was 13 months [95% confidence interval (CI), 10.93-15.08]. The median overall survival (OS) time was 45.3 months (95% CI, 25.01-65.59) and the median progression-free survival (PFS) time was 30.0 months (95% CI, 13.43-46.57). Age (>60 years) was associated with a shorter OS time (P=0.009). Ki-67 (cutoff point 90%) was associated with shorter OS (P=0.037) and shorter PFS (P=0.039) times. No other immunohistochemical markers were associated with prognosis. On multivariate analysis, age (>60 years) was associated with shorter OS time (P=0.038), but immunophenotype and expression status of Ki-67, CD10, BCL-6 and BCL-2 did not predict prognosis. In conclusion, high Ki-67 expression may predict poor prognosis in PCNSL. The present study was limited by its sample size and short follow-up time. This requires more evidence to further clinical study.

Methotrexate plus idarubicin improves outcome of patients with primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma with poor long-term survival. This study assessed methotrexate (MTX) plus idarubicin (IDA) in treating patients of PCNSL comparing to MTX alone therapy. A total of 100 patients were retrospectively enrolled and subjected to MTX alone (n = 52) and MTX plus IDA (n = 48). The completed response (CR) rate in patients treated with MTX plus IDA was 62.50%, and overall response (OR) rate was 79.17%, which in MTX alone cohort were 42.31% and 63.46% respectively. Median progression-free survival (PFS) of patients treated with MTX plus IDA was significantly better than those treated with MTX alone (18.35 months vs.8.45months, P = 0.000). The MTX plus IDA regimen exhibited a significantly better control of PCNSL. Further studies would be needed to confirm these results.

Primary pediatric mid-brain lymphoma: Report of a rare pediatric tumor in a rare location

Primary central nervous system lymphoma (PCNSL) is a rare disease in pediatric age group. A thirteen-year-old male child presented with complaints of headache for six months, vomiting and diplopia for three days. Magnetic resonance imaging of the brain showed a single lesion of 1.7 cm × 1.6 cm × 1.6 cm in the mid brain and tectum. He underwent a gross total resection of the tumor. The histopathological evaluation revealed B cell high grade non Hodgkin lymphoma. The patient was treated with High dose methotrexate and cranio spinal radiation. The patient was alive without disease 12 mo after completion of treatment. This case highlights importance of keeping PCNSL as differential in brain stem lesions of pediatric patients also. Radiation and chemotherapy remains the most important treatment for such patients.

Expression of Tim-1 in primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) is a distinct subtype of extranodal lymphoma with aggressive clinical course and poor outcome. As increased IL‐10/IL‐6 ratio is recognized in the cerebrospinal fluid (CSF) of PCNSL patients, we hypothesized that PCNSL might originate from a population of B cells with high IL‐10‐producing capacity, an equivalent of “regulatory B cells” in mice. We intended in this study to clarify whether Tim‐1, a molecule known as a marker for regulatory B cells in mice, is expressed in PCNSL. By immunohistochemical analysis, Tim‐1 was shown to be positive in as high as 54.2% of PCNSL (26 of 58 samples), while it was positive in 19.1% of systemic diffuse large B‐cell lymphoma (DLBCL) samples (17 of 89 samples; P < 0.001). Tim‐1 expression positively correlated with IL‐10 expression in PCNSL (Cramer's V = 0.55, P < 0.001), and forced expression of Tim‐1 in a PCNSL cell line resulted in increased IL‐10 secretion, suggesting that Tim‐1 is functionally linked with IL‐10 production in PCNSL. Moreover, soluble Tim‐1 was detectable in the CSF of PCNSL patients, and was suggested to parallel disease activity. In summary, PCNSL is characterized by frequent Tim‐1 expression, and its soluble form in CSF may become a useful biomarker for PCNSL.

Prognostic role of tumour-infiltrating inflammatory cells in brain tumours: literature review

PURPOSE OF REVIEW

Both primary and metastatic brain tumours pose a significant and unmet clinical need. Immune cells infiltrating the tumour have been shown to affect the clinical course of various extracranial tumour types, but there is little knowledge on the role of tumour-infiltrating immune cells in brain tumours. Thus, the aim of this review was to recapitulate the reports on immune infiltrates in brain tumours and their prognostic significance.

RECENT FINDINGS

Immune infiltrates composed of various lymphocyte subsets and microglia/macrophages are frequently observed in brain tumours; however, their density and prognostic role seem to differ between tumour types. Central nervous system (CNS) metastases, particularly of melanoma, lung cancer and renal cell cancer, commonly show high amounts of tumour-infiltrating lymphocytes and tumour-infiltrating lymphocytes density strongly correlate with patient's overall survival times in patients with CNS metastases. In gliomas and primary CNS lymphomas, some studies also suggest a prognostic role of immune cell infiltration; however, methodological issues such as low sample size and retrospective study designs with heterogeneous patient populations preclude definite conclusions. Meningiomas typically harbour inflammatory infiltrates, but their correlation with the clinical course is unclear because of the lack of studies correlating immune cell infiltrates with outcome parameters.

SUMMARY

The available literature suggests a relevant role of immune infiltrates in the clinical course of some brain tumour types; however, further studies are required to better understand the interaction of the immune system and CNS neoplasms and to explore therapeutic opportunities with immunotherapies such as vaccines or immune checkpoint modulators.

Molecular MRI differentiation between primary central nervous system lymphomas and high-grade gliomas using endogenous protein-based amide proton transfer MR imaging at 3 Tesla

OBJECTIVES

To show the ability of using the amide proton transfer-weighted (APTW) MRI signals as imaging biomarkers to differentiate primary central nervous system lymphomas (PCNSLs) from high-grade gliomas (HGGs).

METHODS

Eleven patients with lymphomas and 21 patients with HGGs were examined. Magnetization-transfer (MT) spectra over an offset range of ± 6 ppm and the conventional MT ratio (MTR) at 15.6 ppm were acquired. The APTW signals, total chemical-exchange-saturation-transfer signal (integral between 0 and 5 ppm, CEST total), and MTR signal were obtained and compared between PCNSLs and HGGs. The diagnostic performance was assessed with the receiver operating characteristic (ROC) curve analysis.

RESULTS

The PCNSLs usually showed more homogeneous APTW hyperintensity (spatially compared to normal brain tissue) than the HGGs. The APTW max, APTW max-min and CEST total signal intensities were significantly lower (P < 0.05, 0.001 and 0.05, respectively), while the APTW min and MTR were significantly higher (both P < 0.01) in PCNSL lesions than in HGG lesions. The APTW values in peritumoral oedema were significantly lower for PCNSLs than for HGGs (P < 0.01). APTW max-min had the highest area under the ROC curve (0.963) and accuracy (94.1 %) in differentiating PCNSLs from HGGs.

CONCLUSIONS

The protein-based APTW signal would be a valuable MRI biomarker by which to identify PCNSLs and HGGs presurgically.

KEY POINTS

PCNSLs overall showed more homogeneous APTW hyperintensity than HGGs. Maximum APTW signals were lower in PCNSL lesions than in HGG lesions. MTR signals were higher in PCNSLs than in HGGs. APTW heterogeneity had the highest accuracy in differentiating PCNSLs from HGGs.

Prognostic impact of B-cell lymphoma 6 in primary CNS lymphoma

BACKGROUND

We investigated the prognostic significance of B-cell differentiation status and common B-cell differentiation markers in a post hoc analysis of 119 patients with primary CNS lymphoma (PCNSL) homogeneously receiving high-dose methotrexate (HDMTX)-based chemotherapy within the prospective G-PCNSL-SG1 trial.

METHODS

We evaluated protein expression of B-cell lymphoma 2 (BCL2), BCL6, CD10, and multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4) by immunohistochemistry and analyzed the association with survival.

RESULTS

The median follow-up of all patients was 67.5 months. Median progression-free survival (PFS) was 10.61 months (95% CI: 4.23-17.00). Median overall survival (OS) was 28.85 months (95% CI: 17.96-39.73). Eighty-nine tumors expressed BCL2 (92.7%), 24 (20.5%) expressed CD10, 60 (54.1%) expressed BCL6, and 87 (79.0%) expressed MUM1/IRF4. On the basis of the Hans algorithm, 80 tumors (73.4%) were classified to the non-germinal center B group, suggesting a post-germinal center origin of PCNSL. Expression of BCL6 (cutoff point 30%), but none of the other markers, was associated with shorter PFS (P = .047) and OS (P = .035). On multivariate analysis, BCL6 expression was associated with shorter PFS (hazard ratio: 1.95, 95% CI: 1.22-3.12, P = .005) but not OS (hazard ratio: 1.85, 95% CI: 0.71-4.80, P = .21). Classification according to Hans algorithm and expression status of the single B-cell markers BCL2, CD10, and MUM1/IRF4 did not correlate with prognosis.

CONCLUSION

The findings are limited by the fact that only 23% of all G-PCNSL-SG1 patients could be included in the analysis. If validated in an independent cohort, BCL6 may assume clinical relevance as an unfavorable prognostic biomarker in PCNSL.

Primary central nervous system lymphoma: current state of anti-CD20 therapy and appraisal of reported response criteria

Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin's lymphoma which is confined to the central nervous system and may also affect intraocular structures. Despite high initial rates of response to methotrexate-based chemotherapy, more than 50% of patients will experience relapse and about 10% have disease that is refractory to chemotherapy. Outcome in patients who fail treatment is very poor, and therefore new therapeutic approaches that may increase the rate of complete response and the proportion of durable remission are sought. Based on the pivotal role that anti-CD20 therapy now plays in the treatment outcome of aggressive systemic B-cell lymphomas, a similar approach is commonly being adapted for PCNSL despite the lack of evidence for its effectiveness. This review examines the current status and level of evidence for the use of monoclonal antibodies against the CD20 surface antigen, which is present on normal and malignant B-cells in PCNSL. The review covers both systemic and local (intracerebrospinal fluid or intravitreal) administration of CD20 monoclonal antibodies in PCNSL. In addition, it scrutinizes the response criteria commonly reported for evaluation of treatment outcome. The importance of differentiating unconfirmed complete response from partial response is outlined and the lack of consensus on response criteria for atypical imaging presentations of PCNSL is delineated.

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.

Characteristics and prognosis of B-cell lymphoma in HIV-infected children in the HAART era

Chronic HIV infection leads to increased risk of non-Hodgkin B-cell lymphoma. However, only few recent data are available about their current management and prognosis in HIV-infected children since the advent highly active antiretroviral therapy (HAART). This multicenter retrospective study describes the 12 cases of B-cell non-Hodgkin lymphoma diagnosed in HIV-infected children in France between 1996 and 2009. All children had moderate to severe immunosuppression and high viral load at the time of diagnosis. Nine children had extracerebral primary sites and 3 had a primary central nervous system lymphoma. Eight patients had Burkitt lymphoma; 4 had diffuse large B-cell lymphoma. Concomitantly with HAART, all children with extracerebral lymphoma received intensive chemotherapy according to LMB protocol, those with primary central nervous system lymphoma received high-dose methotrexate. No toxicity-related deaths occurred. Ten patients entered complete remission (CR), 2 died of tumor progression despite a second line of therapy. No relapses occurred after CR (median follow-up, 72 mo). Thus, prognosis of patients unresponsive to first-line lymphoma treatment remains poor, but relapse seems to be rare when CR is achieved. Children without severe comorbidities can tolerate intensive chemotherapy with a mandatory HAART treatment, taking into account drug interactions.