Primary Central Nervous System Lymphoma in Elderly Patients: Management and Perspectives

The management of elderly patients suffering from primary central nervous system (CNS) lymphoma, who represent a rapidly growing population, is challenging. Despite the advances made in PCNSL treatment, the prognosis in older patients remains unsatisfactory. The high risk of systemic and CNS toxicity induced by a high-dose chemotherapy regimen and radiation therapy, respectively, limits the use of consolidation phase treatments in elderly patients and contributes to the poor outcome of these patients. Here, we review the current treatment strategies and ongoing trials proposed for elderly PCNSL patients.

Targeted Therapies and Immune Checkpoint Inhibitors in Primary CNS Lymphoma

This review article outlines the current development of emerging treatment strategies for primary central nervous system lymphoma, a rare brain tumor with, thus far, limited therapeutic options. Small molecule targeted tyrosine kinase inhibitors, immunomodulatory agents, and immune checkpoint inhibitors will be discussed. The mechanisms of action, results of completed clinical studies, ongoing clinical trials, and future perspectives are summarized. Among the most promising clinical developments in the field of CNS lymphomas is ibrutinib, an inhibitor of Bruton's tyrosine kinase, which relays activation of nuclear factor kappa B upon integration of constitutive B cell receptor and Toll-like receptor signals. Down-stream of nuclear factor kappa B, the thalidomide analogs lenalidomide and pomalidomide exert immunomodulatory functions and are currently explored against CNS lymphomas. Finally, immune checkpoint inhibitors, such as drugs targeting the PD-1 pathway, may become novel therapeutic options to unleash anti-tumor immunity in patients with primary CNS lymphoma.

Is There an Indication for First Line Radiotherapy in Primary CNS Lymphoma?

Background: Primary CNS Lymphoma is a rare and severe but potentially curable disease. In the last thirty years treatment has changed significantly. Survival times increased due to high-dose methotrexate-based chemotherapy. With intensive regimens involving autologous stem cell transplantation (ASCT), 4-year survival rates of more than 80% can be reached. However, this treatment regimen is not feasible in all patients, and is associated with some mortality. Methods: In this review, current evidence regarding the efficacy and toxicity of radiotherapy in PCNSL shall be summarized and discussed mainly based on data of controlled trials. Results: Being the first feasible treatment whole brain radiotherapy (WBRT) was initially used alone, and later as a consolidating treatment after high-dose methotrexate-based chemotherapy. More recently, concerns regarding activity and neurotoxicity of standard dose WBRT limited its use. On the contrary, latest evidence of some phase II trials suggests efficacy of consolidating WBRT is comparable to ASCT. After complete remission reduced dose WBRT appears as a feasible concept with decreased neurotoxicity. Evidence for use of local stereotactic radiotherapy is very limited. Conclusion: Radiotherapy has a role in the treatment of PCNSL patients not suitable to ASCT, e.g., as consolidating reduced dose WBRT after complete response. Local stereotactic radiotherapy for residual disease should be examined in future trials.

A genome-wide association study identifies susceptibility loci for primary central nervous system lymphoma at 6p25.3 and 3p22.1: a LOC Network study

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare form of extra-nodal non-Hodgkin lymphoma. PCNSL is a distinct subtype of non-Hodgkin lymphoma, with over 95% of tumors belonging to the diffuse large B-cell lymphoma (DLBCL) group. We have conducted a genome-wide association study (GWAS) on immunocompetent patients to address the possibility that common genetic variants influence the risk of developing PCNSL.

METHODS

We performed a meta-analysis of 2 new GWASs of PCNSL totaling 475 cases and 1134 controls of European ancestry. To increase genomic resolution, we imputed >10 million single nucleotide polymorphisms using the 1000 Genomes Project combined with UK10K as reference. In addition we performed a transcription factor binding disruption analysis and investigated the patterns of local chromatin by Capture Hi-C data.

RESULTS

We identified independent risk loci at 3p22.1 (rs41289586, ANO10, P = 2.17 × 10-8) and 6p25.3 near EXOC2 (rs116446171, P = 1.95 x 10-13). In contrast, the lack of an association between rs41289586 and DLBCL suggests distinct germline predisposition to PCNSL and DLBCL. We found looping chromatin interactions between noncoding regions at 6p25.3 (rs11646171) with the IRF4 promoter and at 8q24.21 (rs13254990) with the MYC promoter, both genes with strong relevance to B-cell tumorigenesis.

CONCLUSION

To our knowledge this is the first study providing insight into the genetic predisposition to PCNSL. Our findings represent an important step in defining the contribution of common genetic variation to the risk of developing PCNSL.

Efficacy and safety of intravitreal methotrexate for vitreo-retinal lymphoma - 20 years of experience

Vitreo-retinal lymphoma (VRL) is the most common intraocular lymphoma and is highly associated with central nervous system (CNS) lymphoma (CNSL), both posing a therapeutic challenge. We investigated patients' characteristics, efficacy and safety of intravitreal methotrexate (MTX) injections and their outcomes over 20 years. The records of 129 patients diagnosed between 1997 and 2018 were retrospectively reviewed. Lymphoma involved both the CNS and vitreo-retina (49%), solely the CNS (37%) or solely the vitreo-retina (14%). In all, 45·5% of the patients with CNSL either presented with VRL or developed it after a mean (±SE) of 85·7 (7·3) months. In all, 66·0% of the patients diagnosed with VRL either presented with CNSL or developed it after a mean (±SE) 42·6 (7·6) months. The 81 patients with VRL (134 eyes) received a mean (±SD) of 19 (7) injections; however, only 5 (4) injections were needed to reach complete remission. Local recurrence occurred in two of the 81 patients. Overall, 80·2% of eyes had an initial moderate-severe visual loss, and >50% of them improved. Reversible keratopathy was the most prevalent side-effect. A total of 18·5% developed intraocular pressure (IOP) elevation due to angle neovascularisation after 16 injections, which could be reversed with prompt intravitreal injection of bevacizumab. Intravitreal MTX injections are a safe and effective treatment for VRL. Fewer injections (15) may offer similar results with fewer side-effects.

Glioblastoma and primary central nervous system lymphoma: differentiation using MRI derived first-order texture analysis - a machine learning study

OBJECTIVES

To evaluate the diagnostic performance of multiple machine learning classifier models derived from first-order histogram texture parameters extracted from T1-weighted contrast-enhanced images in differentiating glioblastoma and primary central nervous system lymphoma.

METHODS

Retrospective study with 97 glioblastoma and 46 primary central nervous system lymphoma patients. Thirty-six different combinations of classifier models and feature selection techniques were evaluated. Five-fold nested cross-validation was performed. Model performance was assessed for whole tumour and largest single slice using receiver operating characteristic curve.

RESULTS

The cross-validated model performance was relatively similar for the top performing models for both whole tumour and largest single slice (area under the curve 0.909-0.924). However, there was a considerable difference between the worst performing model (logistic regression with full feature set, area under the curve 0.737) and the highest performing model for whole tumour (least absolute shrinkage and selection operator model with correlation filter, area under the curve 0.924). For single slice, the multilayer perceptron model with correlation filter had the highest performance (area under the curve 0.914). No significant difference was seen between the diagnostic performance of the top performing model for both whole tumour and largest single slice.

CONCLUSIONS

T1 contrast-enhanced derived first-order texture analysis can differentiate between glioblastoma and primary central nervous system lymphoma with good diagnostic performance. The machine learning performance can vary significantly depending on the model and feature selection methods. Largest single slice and whole tumour analysis show comparable diagnostic performance.

MYD88 L265P mutation and interleukin-10 detection in cerebrospinal fluid are highly specific discriminating markers in patients with primary central nervous system lymphoma: results from a prospective study

Reliable biomarkers are needed to avoid diagnostic delay and its devastating effects in patients with primary central nervous system (CNS) lymphoma (PCNSL). We analysed the discriminating sensitivity and specificity of myeloid differentiation primary response (88) (MYD88) L265P mutation (mut-MYD88) and interleukin-10 (IL-10) in cerebrospinal fluid (CSF) of both patients with newly diagnosed (n = 36) and relapsed (n = 27) PCNSL and 162 controls (118 CNS disorders and 44 extra-CNS lymphomas). The concordance of MYD88 mutational status between tumour tissue and CSF sample and the source of ILs in PCNSL tissues were also investigated. Mut-MYD88 was assessed by TaqMan-based polymerase chain reaction. IL-6 and IL-10 messenger RNA (mRNA) was assessed on PCNSL biopsies using RNAscope technology. IL levels in CSF were assessed by enzyme-linked immunosorbent assay. Mut-MYD88 was detected in 15/17 (88%) PCNSL biopsies, with an 82% concordance in paired tissue-CSF samples. IL-10 mRNA was detected in lymphomatous B cells in most PCNSL; expression of IL-6 transcripts was negligible. In CSF samples, mut-MYD88 and high IL-10 levels were detected, respectively, in 72% and 88% of patients with newly diagnosed PCNSL and in 1% of controls; conversely, IL-6 showed a low discriminating sensitivity and specificity. Combined analysis of MYD88 and IL-10 exhibits a sensitivity and specificity to distinguish PCNSL of 94% and 98% respectively. Similar figures were recorded in patients with relapsed PCNSL. In conclusion, high detection rates of mut-MYD88 and IL-10 in CSF reflect, respectively, the MYD88 mutational status and synthesis of this IL in PCNSL tissue. These biomarkers exhibit a very high sensitivity and specificity in detecting PCNSL both at initial diagnosis and relapse. Implications of these findings in patients with lesions unsuitable for biopsy deserve to be investigated.

Diffusion-weighted MR imaging histogram analysis in HIV positive and negative patients with primary central nervous system lymphoma as a predictor of outcome and tumor proliferation

INTRODUCTION

Ki-67 expression, a marker of tumor proliferation, is considered a prognostic factor in primary CNS lymphoma (PCNSL). Apparent diffusion coefficient (ADC) parameters have also been proposed as imaging biomarkers for tumor progression and proliferative activity in various malignancies. The aim of this study is to investigate the correlation between ADC parameters, Ki-67 expression, overall survival (OS) and progression free survival (PFS) in PCNSL.

MATERIALS AND METHODS

Patients diagnosed with PCNSL at MD Anderson Cancer Center between Mar 2000 and Jul 2016 and at Ben Taub Hospital between Jan 2012 and Dec 2016 were retrospectively studied. Co-registered ADC maps and post-contrast images underwent whole tumor segmentation. Normalized ADC parameters (nADC) were calculated as the ratio to normal white matter. Percentiles of nADC were calculated and were correlated with Ki-67 using Pearson's correlation coefficient and clinical outcomes (OS and PFS) using Cox proportional hazards models.

RESULTS

Selection criteria yielded 90 patients, 23 patients living with HIV (PLWH) and 67 immunocompetent patients. Above median values for nADC_mean, nADC₁₅, nADC₇₅ and nADC₉₅ were associated with improved OS in all patients (p < 0.05). Above median values for nADC_min, nADC_mean, nADC₁, nADC₅ and kurtosis were associated with improved PFS in all patients (p < 0.05). In patients with available Ki-67 expression data (n = 22), nADC_mean, nADC₁₅ and nADC₇₅ inversely correlated with Ki-67 expression (p < 0.05). For PLWH, there was no correlation between ADC parameters and Ki-67 expression or clinical outcomes.

CONCLUSIONS

ADC histogram analysis can predict tumor proliferation and survival in immunocompetent patients with PCNSL, but with limited utility in PLWH.

Persistent hiccups and Horner's syndrome in a case of primary CNS lymphoma with diffuse cerebral, hypothalamic and lateral brainstem involvement - An exercise in clinical neuroanatomy

We present a case of a 42-year-old male presenting with persistent hiccups and a Horner's syndrome, among other symptoms and signs of hypothalamic and brainstem dysfunction. He had a biopsy-proven diffuse infiltrative large primary CNS B-cell lymphoma involving the left fronto-temporal hemisphere, diencephalon and brainstem. The aim of this case report is to highlight key clinical and neuro-anatomical correlations that bring light to the art of the clinical examination.

Life threatening rare lymphomas presenting as longitudinally extensive transverse myelitis: a diagnostic challenge

Background and aims - Description of two cases of rare intravascular large B-cell lymphoma and secondary T-cell lymphoma diagnosed postmortem, that manifested clinically as longitudinally extensive transverse myelitis (LETM). We discuss causes of diagnostic difficulties, deceptive radiological and histological investigations, and outline diagnostic procedures based on our and previously reported cases. Case reports - Our first case, a 48-year-old female was admitted to the neurological department due to paraparesis. MRI suggested LETM, but the treatments were ineffective. She died after four weeks because of pneumonia and untreatable polyserositis. Pathological examination revealed intravascular large B-cell lymphoma (IVL). Our second case, a 61-year-old man presented with headache and paraparesis. MRI showed small bitemporal lesions and lesions suggesting LETM. Diagnostic investigations were unsuccessful, including tests for possible lymphoma (CSF flow cytometry and muscle biopsy for suspected IVL). Chest CT showed focal inflammation in a small area of the lung, and adrenal adenoma. Brain biopsy sample from the affected temporal area suggested T-cell mediated lymphocytic (paraneoplastic or viral) meningoencephalitis and excluded diffuse large B-cell lymphoma. The symptoms worsened, and the patient died in the sixth week of disease. The pathological examination of the presumed adenoma in the adrenal gland, the pancreatic tail and the lung lesions revealed peripheral T-cell lymphoma, as did the brain and spinal cord lesions. Even at histological examination, the T-cell lymphoma had the misleading appearance of inflammatory condition as did the MRI. Conclusion - Lymphoma can manifest as LETM. In cases of etiologically unclear atypical LETM in patients older than 40 years, a random skin biopsy (with subcutaneous adipose tissue) from the thigh and from the abdomen is strongly recommended as soon as possible. This may detect IVL and provide the possibility of prompt chemotherapy. In case of suspicion of lymphoma, parallel examination of the CSF by flow cytometry is also recommended. If skin biopsy is negative but lymphoma suspicion remains high, biopsy from other sites (bone marrow, lymph nodes or adrenal gland lesion) or from a simultaneously existing cerebral lesion is suggested, to exclude or prove diffuse large B-cell lymphoma, IVL, or a rare T-cell lymphoma.

Diagnostic Yield of Body CT and Whole-Body FDG PET/CT for Initial Systemic Staging in Patients With Suspected Primary CNS Lymphoma: A Systematic Review and Meta-Analysis

BACKGROUND. Several guidelines recommend body imaging for the initial work-up of patients with suspected primary CNS lymphoma, to exclude subclinical systemic involvement. However, to our knowledge, the diagnostic yield of body CT (contrast-enhanced CT of the chest, abdomen, and pelvis) and whole-body FDG PET/CT for the evaluation of subclinical systemic lymphoma has not yet been systematically evaluated. OBJECTIVE. The purpose of this study was to investigate and compare the diagnostic yield of body CT and whole-body FDG PET/CT in detecting subclinical systemic lymphoma in patients with suspected primary CNS lymphoma. EVIDENCE ACQUISITION. A systematic search of the MEDLINE and EMBASE databases through July 5, 2020, was conducted to identify studies evaluating the diagnostic yield of body CT or whole-body FDG PET/CT in detecting subclinical systemic lymphoma in patients with suspected primary CNS lymphoma. Pooled estimates of the diagnostic yield of both imaging modalities were calculated using the DerSimonian and Laird random-effects model. The false referral rate and the rate of incidental secondary malignancy were also pooled. EVIDENCE SYNTHESIS. Nine original articles on studies evaluating a total of 1040 patients were included. In detecting subclinical systemic lymphoma, the pooled diagnostic yields of body CT and whole-body FDG PET/CT were 2.5% (95% CI, 1.5-3.9%) and 4.9% (95% CI, 2.8-8.5%), respectively. In the subgroup analysis, the diagnostic yield of whole-body FDG PET/CT was significantly higher than that of body CT (p = .03). Four studies reported changes in the management plan: the R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone) regimen with or without radiation therapy was added if extracranial lymphoma involvement was detected by body CT or whole-body FDG PET/CT. The pooled false referral rate of whole-body FDG PET/CT was 5.3% (95% CI, 2.2-12.0%). The pooled rate of incidental secondary malignancy detected on whole-body FDG PET/CT was 3.1% (95% CI, 1.7-5.6%). CONCLUSION. Body imaging should be used in the initial workup of patients with suspected primary CNS lymphoma, to exclude systemic involvement. Whole-body FDG PET/CT may be a better alternative to body CT. CLINICAL IMPACT. Our results support current National Comprehensive Cancer Network guidelines for the use of body imaging to exclude subclinical systemic involvement in patients with suspected primary CNS lymphoma.

Primary Central Nervous System Lymphoma Presenting as Parkinsonism with Atypical MRI Findings and Elevated 14-3-3 Protein

Primary central nervous system lymphoma (PCNSL) is a rare neoplasm with an incidence of 2 to 3% of all CNS malignancies. The diagnosis can be challenging, especially with atypical presentations. Movement disorders can be one of the rare presentations of PCNSL. Here, we present an unusual case of gradually progressing Parkinsonism with an elevation of cerebrospinal fluid (CSF) 14–3-3 protein and atypical imaging findings found to have PCNSL. A 76-year-old female patient presented with gait and intermittent speech difficulty. Initial workup revealed a contrast-enhancing lesion in the bilateral putamen and head of caudate without any mass effect. Her symptoms were rapidly progressed over 6 months and presented with mild dysarthria, bradykinesia, mild rigidity, and reduced left arm swinging. These features were consistent with Parkinsonism. The repeat imaging showed the progression of hyperintensities in the bilateral putamen. The patient underwent a stereotypic biopsy of the right caudate nucleus, which revealed PCNSL. She was treated with high-dose methotrexate and is currently in remission. Diagnosis of movement disorders remains clinical and rapid progression of symptoms, and atypical presentation must warrant further imaging and workup.

On point in primary CNS lymphoma

Primary CNS lymphoma (PCNSL) is an aggressive brain tumor that represents a significant challenge both to elucidate its biological pathogenesis as well as to develop definitive precision medicines with minimal collateral toxicity. We highlight the key issues in diagnosis and treatment and focus on emerging technologies, current options among consolidation strategies, and biological agents. We anticipate that further development of molecular diagnostics and molecular imaging approaches that elucidate minimal residual disease in brain parenchyma, leptomeninges, intraocular compartments and even bone marrow will greatly impact the delivery and timing of cytotoxic and biological therapies. Implementation of these approaches is likely essential to clarify ongoing discrepancies in the interpretation of clinical trial results that currently are based on relatively unrefined definitions of response. While the results of early phase investigations involving ibrutinib and the IMiD agents, lenalidomide, pomalidomide, as well as avadomide, strongly support the hypothesis that the B-cell receptor (BCR) pathway, involving MYD88 and CD79B and NF-kB activation, is critical to the pathogenesis of PCNSL, much work is needed to elucidate mechanisms of resistance. Similarly, development of strategies to overcome immunosuppressive mechanisms that are upregulated in the tumor microenvironment is a high priority. Finally, ongoing evidence supports the hypothesis that the blood-brain barrier represents a significant impediment to efficient brain tumor penetration of novel therapeutic agents and innovative strategies of drug delivery remain essential to further improve outcomes.

"Slow and Steady" Infiltrates the Brain: An Autopsy Report of Lymphomatosis Cerebri

Primary central nervous system lymphomas (PCNSL) usually present as single or multiple lesions with mass effect involving the cerebral hemispheres or basal ganglia. An extremely rare pattern of involvement termed "Lymphomatosis cerebri" (LC) presents as diffuse, non-enhancing infiltrative lesions without mass effect. We describe the clinical, radiological, and autopsy findings of one such rare example with a patient presenting with a short history of fever, memory loss, and progressive cognitive decline. Because of subtle yet rapidly progressive clinical symptoms and overlapping neuroimaging features, the diagnosis of LC is challenging with wide ranging differential diagnoses. The dilemma in diagnosing such lesions can lead to delay in diagnosis and institution of appropriate management. Thus, knowledge about its imaging and morphological features is very critical for correct categorization and to avoid potential misdiagnosis of this often-missed disease.

A case of primary central nervous system lymphoma presenting as a shunt complication

The authors describe an 82-year-old female with a right frontal ventriculoperitoneal (VP) shunt for long-standing normal pressure hydrocephalus (NPH) who presented with worsening incontinence and gait instability. She was found to have right lateral ventricle collapse around the shunt catheter and subsequently underwent shunt revision, which failed to improve her symptoms. Magnetic resonance imaging (MRI) was obtained on postoperative day two, which demonstrated a ventricular lesion. Endoscopic brain biopsy was performed and a diagnosis of primary central nervous system lymphoma (PCNSL) was made. The authors believe this is the first published case of PCNSL presenting as a VP shunt complication in a patient with NPH.

Immunohistochemistry for c-myc and bcl-2 overexpression improves risk stratification in primary central nervous system lymphoma

Overexpression of bcl‐2 and c‐myc are defining features of double‐expressor‐lymphoma (DEL) but may also occur separately in patients with primary central nervous system lymphoma (PCNSL). Despite all progress in optimizing treatment regimen, there is lack of sufficient risk stratification models. Here, we first describe the relationship between DEL biology, the National Comprehensive Cancer Network International Prognostic Index (NCCN‐IPI), treatment response, disease progression, and mortality in PCNSL. In this study, we determined c‐myc and bcl‐2 status immunohistochemically in samples of 48 patients with newly diagnosed PCNSL and followed these patients for a median interval of 6.2 years. Twelve, 18, and 17 patients harbored none, one, or both DEL features. Corresponding overall response rates after first‐line therapy were strongly associated with DEL biology (100%, 42%, and 44% in patients with 0, 1, or 2 DEL features). Patients with one or both DEL features had a 5‐fold and 13‐fold higher 5‐year risk of progression and/or death than patients without DEL features. These associations prevailed after adjusting for the NCCN‐IPI. DEL improved the discriminatory capability of the NCCN‐IPI (P = .0001). Furthermore, we could show that addition of DEL biology to the NCCN‐IPI significantly improved the score's discriminatory potential both toward progression‐free survival (increase in Harell's c = 0.15, P = .005) and overall survival (increase in Harell's c = 0.11, P = .029). In conclusion, DEL biology is a strong and simple‐to‐use predictor of adverse outcome in PCNSL. Addition of DEL to the NCCN‐IPI improves its prognostic potential. Disease progression from PCNSL harboring both DEL features is invariably fatal. This defines a novel PCNSL patient subset with a great unmet need for improved therapy.

Ibrutinib in primary central nervous system diffuse large B-cell lymphoma

The standard regimen for the treatment of newly diagnosed primary CNS lymphoma (PCNSL) remains regimens that contain high-dose methotrexate (MTX). While these regimens can provide control for some patients, there is a dearth of options for the treatment of patients with PCNSL who cannot tolerate MTX-containing regimens, or whose cancers are refractory to MTX. In this article, we review a promising new option; ibrutinib, a Bruton tyrosine kinase inhibitor, for patients with relapsed and refractory PCNSL.

A new prognostic score for disease progression and mortality in patients with newly diagnosed primary CNS lymphoma

Background

Although various prognostic models for primary central nervous system lymphoma (PCNSL) have been developed, there is no consensus regarding the optimal prognostic index. We aimed to evaluate potential prognostic factors and construct a novel predictive model for PCNSL patients.

Methods

We enrolled newly diagnosed PCNSL patients between 2003 and 2015. The primary endpoint was progression‐free survival (PFS), and the secondary endpoint was overall survival (OS). The prognostic factors identified using multivariate Cox proportional hazards models were used to develop a predictive model. We subsequently validated the prognostic model in an independent cohort. We also evaluated the validity of the existing scores: the International Extranodal Lymphoma Study Group (IELSG), the Nottingham/Barcelona (NB), and the Memorial Sloan‐Kettering Cancer Center models (MSKCC).

Results

We identified 101 patients with newly diagnosed PCNSL at our center. Multivariate analysis showed that age ≥80, deep brain lesions, and ECOG ≥2 were independent risk factors of PFS. Assigning one point for each factor, we constructed a novel prognostic model, the Taipei Score, with four distinct risk groups (0‐3 points). The performances of the Taipei Score in discriminating both PFS and OS in the training cohort were significant, and the score was validated in the external validation cohort. The IELSG, NB and MSKCC models had insufficient discriminative ability for either PFS or OS in both cohorts.

Conclusion

The Taipei Score is a simple model that discriminates PFS and OS for PCNSL patients. The score may offer disease risk stratification and facilitate clinical decision‐making.

Primary Pituitary Lymphoma in Immunocompetent Patients: A Report on Two Case Studies and the Review of Literature

Primary pituitary lymphoma (PPL) represents an extremely rare entity. Here, we have reported two recently identified cases of immunocompetent PPL having diffuse large B-cell lymphoma by surgical biopsy. Both patients had hypopituitarism, with one patient developing right ptosis. In both patients, MRI and FDG-PET/CT depicted sellar mass that extended into the cavernous sinus with the right sphenoid also present in one of the patients. No systemic disease was found in these two patients. Surprisingly, we found that both patients had infiltrative lesions in sphenoid sinus mucosa pathologically, but the sphenoid bones that composed the sellar base were visually intact during the biopsy procedure. Chemotherapy was administered to both patients, where one patient achieved remission at the recent follow-up, whereas the other one did not respond to the treatment. The diagnosis of PPL is usually difficult if solely dependent on history, clinical presentation, biochemical indexes, and radiographic findings. We have also updated and reviewed the epidemiologic features, clinical presentations, pathological characteristics, potential mechanisms, therapeutic orientation, and prognostic advances of PPL. A total of 40 cases (including ours and four pediatric patients), histologically diagnosed, were analyzed in terms of clinical presentation, endocrine abnormality, radiological features, pathology, treatment, and follow-up. Hypopituitarism and headache were the most common presentation of PPL, while diabetes insipidus was reported in 13 patients (43.3%). B cell lymphoma was the most common type of pathology, followed by T-cell and NK/T cell. PPL was more invasive in nature at the suprasellar region (72.5%), cavernous sinus (52.5%), and sphenoidal sinus (27.5%) in 29, 21, and 11 patients, respectively. Pediatric patients with PPL seem to be different compared to their adult counterparts in terms of pathogenesis, clinical presentation, and radiological features. The management of PPL usually follows the treatment protocols for PCNSL but has a poor prognosis compared to the pituitary involvement of systemic lymphoma.

Primary Central Nervous System Lymphoma in an Immunocompetent Patient Presenting as Multiple Cerebellar Lesions: A Case Report and Review of Literature

Primary central nervous system (CNS) lymphoma (PCNSL) is an uncommon extranodal non-Hodgkin lymphoma often presenting as a single brain lesion within the CNS. On histopathological evaluation of PCNSL a positive CD10, which is frequently observed in systemic diffuse large B-cell lymphoma, is present in approximately 10% of PCNSL. We describe a case of CD10-positive PCNSL presenting with multiple posterior fossa enhancing lesions in an immunocompetent older woman with a history of breast cancer successfully treated by the RTOG 0227 protocol consisting of pre-irradiation chemotherapy with high-dose methotrexate, rituximab, and temozolomide for 6 cycles, followed by low-dose whole-brain radiation and post-irradiation temozolomide.

Rituximab in primary central nervous system lymphoma-A systematic review and meta-analysis

The CD-20 antibody rituximab is a standard component of treatment of non-Hodgkin B-cell lymphomas, including diffuse large B-cell lymphoma (DLBCL). Primary DLBCL of the central nervous system, also called primary central nervous system lymphoma (PCNSL), is a DLBCL confined to the central nervous system. There has been debate whether intravenous rituximab accumulates sufficiently in the central nervous system to exert an effect. In this systematic review, we assess the benefits and harms of rituximab in the treatment of immunocompetent patients with PCNSL. By searching MEDLINE, CENTRAL, and ClincialTrials.gov up to March 2019, we identified randomized controlled trials (RCTs) investigating the effect of rituximab in patients with PCNSL. We extracted study characteristics and results, assessed risk of bias, performed trial-level random-effects meta-analyses, and graded the certainty of evidence. The protocol was registered with PROSPERO (CRD42019121965). Main outcomes were overall survival (time to death), progression-free survival (time to progression or death), quality of life, grades 3 and 4 toxicity, and treatment-related mortality. We included two RCTs with a total of 343 participants. Overall survival was not statistically significantly improved (HR 0.76; 95% CI, 0.52-1.12; low certainty), with 187 fewer to 39 more deaths after 2 years in 1000 treated patients. Low certainty of evidence indicated that rituximab improved progression-free survival (HR 0.65; 95% CI, 0.45-0.95), which translated into 137 fewer progressions or deaths after 2 years in 1000 treated patients (231 to 18 fewer). None of the RCTs provided data on quality of life. We found no evidence that rituximab increased grades 3 and 4 toxicity or treatment-related mortality (RR 0.53; 95% CI, 0.20-1.37; low certainty). Overall, the available evidence suggests with low certainty that rituximab in combination with methotrexate-based chemotherapy may improve progression-free survival in immunocompetent patients with newly diagnosed PCNSL, the pooled effect estimates did not show evidence for improvement of overall survival.

Risk Prediction for Early Mortality in Patients with Newly Diagnosed Primary CNS Lymphoma

Background: Overall survival of patients with primary CNS lymphoma (PCNSL) has improved since the introduction of immunochemotherapy. However, up to 10-15% of PCNSL patients still die shortly after diagnosis. In the present study, we aimed to investigate the risk factors of early mortality (death within 60 days after diagnosis) in patients with PCNSL.

Methods: We included newly diagnosed PCNSL patients in a tertiary medical center in Taiwan between January 1, 2002 and May 31, 2018. Clinical risk factors were collected and compared between PCNSL patients who had and did not have early mortality.

Results: A total of 133 consecutive patients with PCNSL were included in this study. Approximately 9.8% of the PCNSL patients had early mortality. In multivariate analysis, age ≥ 80 (adjusted hazard ratio [HR] 3.34, 95% confidence interval [CI] 1.01-11.04, p = 0.048) and involvement of the basal ganglia (adjusted HR 4.85, 95% CI 1.47-15.95, p = 0.009) were identified as independent risk factors of early mortality. Use of MTX-based chemotherapy served as an independent protective factor for early mortality (adjusted HR 0.19, 95% CI 0.05-0.67, p = 0.010). Infection and tumor-associated mass effect contributed most to early mortality.

Conclusion: Early mortality is not uncommon in patients with PCNSL. Identification of patients with higher risk may help clinicians with initiating appropriate surveillance and management.

Lenalidomide in combination with intravenous rituximab (REVRI) in relapsed/refractory primary CNS lymphoma or primary intraocular lymphoma: a multicenter prospective 'proof of concept' phase II study of the French Oculo-Cerebral lymphoma (LOC) Network and the Lymphoma Study Association (LYSA)†

BACKGROUND

Primary central nervous system lymphomas (PCNSLs) are mainly diffuse large B-cell lymphomas (DLBCLs) of the non-germinal center B-cell (non-GCB) subtype. This study aimed to determine the efficacy of rituximab plus lenalidomide (R2) in DLBCL-PCNSL.

PATIENTS AND METHODS

Patients with refractory/relapsed (R/R) DLBCL-PCNSL or primary vitreoretinal lymphoma (PVRL) were included in this prospective phase II study. The induction treatment consisted of eight 28-day cycles of R2 (rituximab 375/m2 i.v. D1; lenalidomide 20 mg/day, D1-21 for cycle 1; and 25 mg/day, D1-21 for the subsequent cycles); in responding patients, the induction treatment was followed by a maintenance phase comprising 12 28-day cycles of lenalidomide alone (10 mg/day, D1-21). The primary end point was the overall response rate (ORR) at the end of induction (P0 = 10%; P1 = 30%).

RESULTS

Fifty patients were included. Forty-five patients (PCNSL, N = 34; PVRL, N = 11) were assessable for response. The ORR at the end of induction was 35.6% (95% CI 21.9-51.2) in assessable patients and 32.0% (95% CI 21.9-51.2) in the intent-to-treat analysis, including 13 complete responses (CR)/unconfirmed CR (uCR; 29%) and 3 partial responses (PR; 7%). The best responses were 18 CR/uCR (40%) and 12 PR (27%) during the induction phase. The maintenance phase was started and completed by 18 and 5 patients, respectively. With a median follow-up of 19.2 months (range 1.5-31), the median progression-free survival (PFS) and overall survival (OS) were 7.8 months (95% CI 3.9-11.3) and 17.7 months (95% CI 12.9 to not reached), respectively. No unexpected toxicity was observed. The peripheral baseline CD4/CD8 ratio impacted PFS [median PFS = 9.5 months (95% CI, 8.1-14.8] for CD4/CD8 ≥ 1.6; median PFS = 2.8 months, [95% CI, 1.1-7.8) for CD4/CD8 < 1.6, P = 0.03).

CONCLUSIONS

The R2 regimen showed significant activity in R/R PCNSL and PVRL patients. These results support assessments of the efficacy of R2 combined with methotrexate-based chemotherapy as a first-line treatment of PCNSL.

CLINICAL TRIALS NUMBER

NCT01956695.