Primary CNS lymphoma: clinical presentation, pathological classification, molecular pathogenesis and treatment

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.

Primary Large B-Cell Lymphoma of Immune-Privileged Sites of the Cerebellum: A Case Series and Review of the Literature

Primary large B-cell lymphoma of immune-privileged sites (IP-LBCL) is a rare malignant hematological neoplasm. Involvement of the cerebellum is even rarer and its diagnosis is often difficult to make due to its non-specific clinical and radiological presentation.

METHODS

We reported 3 cases of cerebellar IP-LBCL followed at our hospital and reviewed the medical literature to unravel the peculiarities of this poorly studied entity.

OUTCOMES

Analyzing our cases and reviewing the literature, we could collect and study 26 cases of cerebellar IP-LBCL. To the best of our knowledge, this is the largest cohort of such patients currently published.

CONCLUSION

Cerebellar IP-LBCL presents more often in adult females with cerebellum-related focal neurological signs such as ataxia, headache, and nausea. Histological confirmation is mandatory for a correct diagnosis and treatment and all cases feature diffuse large B-cell lymphoma histopathology. Compared to other encephalic IP-LBCL, cerebellar cases seem to include a higher number of cases with germinal center B-cell phenotype and better survival. These differences may be related to a different immune microenvironment and especially immunoregulation that distinguishes the cerebellum from other areas of the CNS.

Non-Hodgkin B-cell Lymphoma Presenting as a Pituitary Mass

INTRODUCTION: The authors describe the case of a pituitary mass considered from the radiological point of view as a non-secretory adenoma. CASE REPORT: The patient, a 31-year-old male, presented with an intense headache, non-responsive to antalgics, right eye Mydriasis, and semiptosis. An endoscopic transnasal surgery caused important but temporary relief to the patient, who some days later complained of tumefactions in both axillar regions. Pathological diagnosis was of a non-Hodgkin B-cell lymphoma. CONCLUSIONS: Although pituitary involvement is rare in the case of systemic lymphomas, and even rarer among primary central nervous system malignancies, this possibility must become part of differential diagnosis when approaching pituitary masses.

Lymphomas of Central Nervous System

Central nervous system (CNS) lymphoma consists of primary central nervous system lymphoma (PCNSL) and secondary CNS involvement by systemic lymphoma. This chapter focuses on the former. PCNSL is a relative rare disease, accounting for approximately 2.4-4.9% of all primary CNS tumors. It is an extra-nodal variant of non-Hodgkin's lymphoma (NHL), confined to the brain, leptomeninges, spinal cord, and eyes, with no systemic involvement. Recently, elderly patients (≥ 60 years) are increasing. Histologically, B cell blasts, which originate from late germinal center exit B cell, are growing and homing in CNS. Immunohistochemically, these cells are positive for PAX5, CD19, CD20, CD22, and CD79a. PCNSL shows relatively characteristic appearances on CT, MR imaging, and PET. Treatment first line of PCNSL is HD-MTX-based chemotherapy with or without rituximab and irradiation. Severe side-effect of this treatment is delayed onset neurotoxicity, which cause of cognitive impairment. Therefore, combined chemotherapy alone or chemotherapy with reduced-dose irradiation is more recommended for elderly patients. There is no established standard care for relapse of the PCNSLs. Temsirolimus, lenalidomide, temozolomide, and Bruton's tyrosine kinase (BTK) inhibitor ibrutinib are candidates for refractory patients. The prognosis of PCNSL has significantly improved over the last decades (median OS: 26 months, 5-year survival: 31%). Younger than 60 age and WHO performance status less than < or = 1 are associated with a significantly better overall survival.

Multiparametric MR Imaging Features of Primary CNS Lymphomas

Objective

Primary central nervous system lymphomas (PCNS) are relatively rare tumors, accounting for about 4% of all brain tumors. On neuroimaging, they are characterized by a low MR signal in T1, isointense in T2, bright uniform contrast enhancement, and diffusion restriction. The aim of this study is to note the lack of effectiveness of the MR/CT perfusion technique in complex multiparametric imaging in the differential diagnosis of primary lymphomas of the central nervous system in comparison with highly malignant gliomas and brain metastases.

Materials and Methods

This prospective study included 80 patients with CNS tumors examined/operated at the Federal Center for Neurosurgery (Tyumen, Russia) from 2018 to 2021. The patients were divided into 4 groups: group 1 consisted of 33 cases with primary CNS lymphomas (10 cases with atypical manifestations according to perfusion parameters and 23 cases of classic CNS lymphomas), group 2 with anaplastic astrocytomas—14 cases, group 3—23 cases with glioblastomas and group 4—10 cases with solitary metastatic lesions. The study was carried out on a General Electric Discovery W750 3T magnetic resonance tomograph, a Canon Aquilion One multispiral X-ray computed tomograph (Gadovist 7.5 ml, Yomeron 400 mg−50 ml). Additionally, immunohistochemical analysis was carried out with the following markers: CD3, CD20, CD34, Ki-67, VEGF.

Results

It has been established that MR/CT perfusion is not a highly sensitive method for visualizing primary CNS lymphomas, as previously thought, but at the same time, the method has a number of undeniable advantages that make it indispensable in the algorithm of a complex multiparametric diagnostic approach for this type of tumor. Nevertheless, PLCNS is characterized by an atypical manifestation, which is an exception to the rule.

Conclusions

The possibilities of neuroimaging of primary lymphomas, even with the use of improved techniques for collecting MR/CT data, are limited and do not always allow reliable differentiation from other neoplasms.

The Real-World status and risk factors for a poor prognosis in elderly patients with primary central nervous system malignant lymphomas: a multicenter, retrospective cohort study of the Tohoku Brain Tumor Study Group

BACKGROUND

Elderly patients with primary central nervous system malignant lymphoma (EL-PCNSL) may not be given sufficient treatment due to their poor pre-treatment Karnofsky Performance Status (KPS) and comorbidities. Therefore, a retrospective, cohort study was performed to evaluate risk factors associated with a poor prognosis of EL-PCNSL in the Tohoku Brain Tumor Study Group.

METHODS

Patients aged ≥ 71 years with PCNSL were enrolled from eight centers. Univariate analysis was performed with the log-rank test. A Cox proportional hazards model was used for multivariate analysis.

RESULTS

Three of the total 142 cases received best supportive care (BSC). Treatment was given to 30 cases without a pathological diagnosis, 3 cases with cerebrospinal fluid (CSF) cytology, and 100 cases with a pathological diagnosis. After confirmation of no differences in progression-free survival (PFS) and overall survival (OS) between the group treated without pathology and the groups diagnosed by pathology or CSF cytology and between median age ≥ 76 years and < 76 years, a total of 133 patients were studied. The median pre-treatment KPS was 50%. Median PFS and median OS were 16 and 24 months, respectively. Risk factors associated with poor prognosis on Cox proportional hazards model analysis were pre-treatment cardiovascular disease and central nervous system disease comorbidities, post-treatment pneumonia and other infections, and the absence of radiotherapy or chemotherapy.

CONCLUSIONS

Pre-treatment comorbidities and post-treatment complications would affect the prognosis. Radiation and chemotherapy were found to be effective, but no conclusions could be drawn regarding the appropriate content of chemotherapy and whether additional radiotherapy should be used.

A proposed protocol of intravitreal injection of methotrexate for treatment of primary vitreoretinal lymphoma

PURPOSE

Primary central nervous system lymphoma (PCNSL) is a non-Hodgkin lymphoma involving the brain with possible leptomeningeal and ocular involvement. This study aimed to evaluate the safety and efficacy of modified intravitreal injection regimen of methotrexate (MTX) for therapeutic management of vitreoretinal lymphoma.

MATERIALS AND METHODS

Forty human immunodeficiency virus (HIV)-negative Chinese patients with primary vitreoretinal lymphoma were included in this retrospective noncomparative interventional case series study. Patients were treated with a modified protocol of intravitreal injection of MTX (400 µg/0.1 ml) according to the Intensive-Consolidation-Maintenance regimen. The Intensive phase of once-weekly intravitreal injections for 1 month, followed by the Consolidation phase of one injection every 2 weeks for 1 month, and then the Maintenance phase of once monthly for 1 month, for a total of 7 injections. The primary main outcome measures were clinical response to intravitreal chemotherapy, number of injections for clinical remission, progression-free survival (PFS), overall survival (OS), visual acuity (VA), complications during the study period, and cause of death were investigated.

RESULTS

The duration of follow-up from the commencement of injection of MTX was 12-73 months (median 28, 30.55 ± 14.73 months). A total of 61 eyes of 40 patients were cleared clinically from malignant cells after a median 6.57 ± 3.12 (median 6, range 1-14) times of injection of MTX. A second remission was induced in 3 patients, who were treated with a further course of intravitreal chemotherapy after tumour recurred in their eyes. The median PFS and OS were 20.82 months (95% CI 14.64-27.01) and 29.29 months (95% CI 16.16-42.41), respectively. Complications that occurred during the period of treatment and follow-up included corneal epitheliopathy (3 of 61 eyes) and cataract (6 of 61 eyes). There were no cases of maculopathy, vitreous haemorrhage, optic atrophy, and sterile endophthalmitis. No patient had an irreversible loss of vision that could be attributed to the intravitreal injection of MTX.

CONCLUSIONS

It can be concluded that the modified intravitreal injection regimen of MTX is an effective therapeutic approach in inducing clinical remission of intraocular involvement in PCNSL patients, associated with few complications. However, further study needs to be conducted to indicate whether the proposed approach extends life expectancy.

HIGHLIGHTS

Primary central nervous system lymphoma (PCNSL) can involve the vitreous and retina and is associated with a poor clinical outcome, with a survival rate of less than 3 months in absence of undergoing an effective therapeutic strategy. Methotrexate (MTX) is the most efficient cytotoxic drug for patients with vitreoretinal involvement in primary vitreoretinal lymphoma (PVRL), through intravitreal injection of MTX. In our experience, the modified protocol of intravitreal MTX according to the Intensive-Consolidation-Maintenance regimen, was effective in inducing clinical remission of PVRL with few complications. The accumulating clinical results brought us to propose the consideration of this protocol as a good first-line treatment option for PVRL.

Neuroinflammation preceding primary central nervous system lymphoma (PCNSL) - Case reports and literature review

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of extra-nodal non-Hodgkin's lymphoma. Corticosteroids cause transient regression of PCNSL at the radiological and histological level. A growing number of case reports describe histologically confirmed neuroinflammation (sentinel lesions) heralding the development of PCNSL. We present two further cases of sentinel lesions contextualised by a review of past literature. Our aims are to collate existing knowledge on sentinel lesions in PCNSL and explore their pathophysiological significance. Two cases were identified (n = 2) from a cohort of 104 patients with PCNSL referred to a tertiary neurosurgery centre. A literature search identified previously reported cases (n = 14). Median age was 57.5 (range; 26-72); pre-biopsy corticosteroid administration was reported in 50% of cases (n = 8); mean time between biopsies was 10 months (range; 3-60). Common MRI features were homogenous enhancement (10;71.4%) and T2-hyperintensity (11;100%). Histochemical analysis of sentinel lesion biopsy revealed inflammatory CD3/4/5/8-positive T-cells (14; 100%), demyelination (13; 81.3%), rare/scattered CD20-postive B-cells (11;78.6%) and CD68-positive macrophages (10;71.4%). Repeat biopsy confirmed PCNSL in all cases. Waxing and waning CNS inflammation has been identified in 16 patients ultimately diagnosed with PCNSL. Neuro-specialists should be aware of this atypical presentation and maintain a high index of suspicion for lymphoma despite histopathology negative for lymphoma when clinical or radiological features indicate PCNSL.

HIV and spinal cord disease

The epidemiology of spinal cord disease in human immunodeficiency virus (HIV) infection is largely unknown due to a paucity of data since combination antiretroviral therapy (cART). HIV mediates spinal cord injury indirectly, by immune modulation, degeneration, or associated infections and neoplasms. The pathologies vary and range from cytotoxic necrosis to demyelination and vasculitis. Control of HIV determines the differential for all neurologic presentations in infected individuals. Primary HIV-associated acute transverse myelitis, an acute inflammatory condition with pathologic similarities to HIV encephalitis, arises in early infection and at seroconversion. In contrast, HIV vacuolar myelopathy and opportunistic infections predominate in uncontrolled disease. There is systemic immune dysregulation as early as primary infection due to initial depletion of gut-associated lymphoid tissue CD4 cells and allowance of microbial translocation across the gut that never fully recovers throughout the course of HIV infection, regardless of how well controlled. The subsequent proinflammatory state may contribute to spinal cord diseases observed even after cART initiation. This chapter will highlight an array of spinal cord pathologies classified by stage of HIV infection and immune status.

Diagnosis and Treatment of Primary Central Nervous System Angiitis

PURPOSE OF REVIEW

Primary central nervous system angiitis (PCNSA) is a rare disease. Varying clinical pictures coupled with lack of sensitive and specific diagnostic tests lead to challenges in management of these patients. This unfortunately may lead to both under- or over-diagnosis and unnecessary treatment. It is important to recognize the different conditions that may mimic the clinical and radiologic presentation. We present a contemporary literature review that should update physicians who encounter this patient population.

RECENT FINDINGS

Recent additions to the literature in form of case reports and single-center series show that digital subtraction angiography was the most widely used test to diagnose PCNSA. It is also important to note that brain biopsy is still considered "gold standard" and should be pursued as it not only has information that establishes the diagnosis but also may help in ruling out the diagnosis from mimics. In around 39% of suspected cases, an alternate diagnosis was eventually confirmed highlighting the importance of a comprehensive work-up. For treatment, almost all the literature supports the use of glucocorticoids as the initial treatment and if the patient has a relapse or develops steroid toxicity then the second most commonly used agent was cyclophosphamide. There are increasing reports of benefits with other agents such as methotrexate, azathioprine, mycophenolate, infliximab, and etanercept. The diagnosis and management of PCNSA continues to be a challenge. Formation of prospective patient registries with continued immunologic research for novel targets and immunomodulatory modalities may hold promise for future care of these patients.

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

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

Leakage correction improves prognosis prediction of dynamic susceptibility contrast perfusion MRI in primary central nervous system lymphoma

To evaluate whether the cerebral blood volume (CBV) measurement with leakage correction from dynamic susceptibility contrast perfusion weighted imaging can be useful in predicting prognosis for primary central nervous system lymphoma (PCNSL). 46 PCNSL patients were included and classified by radiation therapy (RT) stratification into RT (n = 30) and non-RT (n = 16) groups. The corresponding histogram parameters of normalized CBV (nCBV) maps with or without leakage correction were calculated on contrast-enhanced T1 weighted image (CE T1WI) or on fluid attenuated inversion recovery image. The 75^th percentile nCBV with leakage correction based on CE T1WI (T1 nCBVL_75%) had a significant difference between the short and long progression free survival (PFS) subgroups of the RT group and the non-RT group, respectively. Based on the survival analysis, patients in the RT group with high T1 nCBVL_75% had earlier progression than the others with a low T1 nCBVL_75%. However, patients in the non-RT group with a high T1 nCBVL_75% had slower progression than the others with a low T1 nCBVL_75%. Based on RT stratification, the CBV with leakage correction has potential as a noninvasive biomarker for the prognosis prediction of PCNSL to identify high risk patients and it has a different correlation with the PFS based on the presence of combined RT.

Primary Vitreoretinal Lymphoma: Management of Isolated Ocular Disease

BACKGROUND

The prognosis for patients with primary vitreoretinal is dismal. The close association of primary vitreoretinal lymphoma with primary central nervous system lymphoma is responsible for high rates of mortality. Traditional treatments consist of systemic chemotherapy and whole-brain radiotherapy. The optimal approach for the treatment of isolated primary vitreoretinal lymphoma is unclear.

METHODS

A review of the relevant medical and scientific literature was performed, focusing on the clinical features of primary vitreoretinal lymphoma and the progress made in the management of isolated ocular disease.

RESULTS

Ocular treatment options for primary vitreoretinal lymphoma have recently expanded with the addition of intravitreal chemotherapeutic agents and localized radiation. Based on several retrospective reports, a general shift has been made toward local therapy (eg, orbital radiotherapy, intravitreal chemotherapy) for ocular disease. No prospective, randomized clinical trials yet exist to guide therapy.

CONCLUSIONS

Optimal treatment regimens for isolated primary vitreoretinal lymphoma continue to evolve. Further investigations into novel therapies and protocols are needed to decrease recurrence rates, reduce or prevent central nervous system involvement, and improve rates of overall survival.

Population-based Incidence and Survival for Primary Central Nervous System Lymphoma in Korea, 1999-2009

PURPOSE

Primary central nervous system lymphoma (PCNSL) is an uncommon brain tumor accounting for 2%-5% of all primary brain tumors. Few population-based analyses of survival for patients with PCNSL have been conducted, particularly in Asian countries.

MATERIALS AND METHODS

Using the Korea National Cancer Incidence Database, 1,062 cases of PCNSL newly diagnosed from 1999 to 2009 were analyzed. The crude rate, age-standardized rate (ASR), and annual percent change were calculated. To estimate the observed survival, we restricted the data to between 1999 and 2007 and followed the cases until December 2010. The overall survival was estimated using the Kaplan-Meier method, and piecewise Poisson regression model.

RESULTS

The ASR for PCNSL between 1999 and 2009 was 0.17 per 100,000, and the annual percent change from 1999 to 2009 was 8.8% (p < 0.001). The ASR of males was higher than that of females, and the older groups (60s or over) showed the largest increase in incidence rates. For all ages, the five-year survival from PCNSL was 29.9% between 1999 and 2007. Survival from PCNSL is known to show strong association with age at diagnosis.

CONCLUSION

These results are similar to those of previous studies. Our findings may be helpful to clinicians and patients in determining long-term prognoses for PCNSL.

Quantitative Evaluation of Diffusion and Dynamic Contrast-Enhanced MR in Tumor Parenchyma and Peritumoral Area for Distinction of Brain Tumors

Purpose

To quantitatively evaluate the diagnostic efficiency of parameters from diffusion and dynamic contrast-enhanced MR which based on tumor parenchyma (TP) and peritumoral (PT) area in classification of brain tumors.

Methods

45 patients (male: 23, female: 22; mean age: 46 y) were prospectively recruited and they underwent conventional, DCE-MR and DWI examination. With each tumor, 10–15 regions of interest (ROIs) were manually placed on TP and PT area. ADC and permeability parameters (K^trans, Ve, Kep and iAUC) were calculated and their diagnostic efficiency was assessed.

Results

In TP, all permeability parameters and ADC value could significantly discriminate Low- from High grade gliomas (HGG) (p<0.001); among theses parameters, Ve demonstrated the highest diagnostic power (iAUC: 0.79, cut-off point: 0.15); the most sensitive and specific index for gliomas grading were K^trans (84%) and Kep (89%). While, in PT area, only K^trans could help in gliomas grading (P = 0.009, cut-off point: 0.03 min^-1). Moreover, in TP, mean Ve and iAUC of primary central nervous system lymphoma (PCNSL) and metastases were significantly higher than that in HGG (p<0.003). Further, in PT area, mean K^trans (p≤0.004) could discriminate PCNSL from HGG and ADC (p≤0.003) could differentiate metastases with HGG.

Conclusions

Quantitative ADC and permeability parameters from Diffusion and DCE-MR in TP and PT area, especially DCE-MR, can aid in gliomas grading and brain tumors discrimination. Their combined application is strongly recommended in the differential diagnosis of these tumor entities.

High prevalence of the MYD88 mutation in testicular lymphoma: Immunohistochemical and genetic analyses

The activating mutation of MYD88 has been identified in diffuse large B-cell lymphoma (DLBCL). We investigated the mutational status and both the gene amplification and protein expression of MYD88 in 23 cases of testicular DLBCL. To detect the MYD88 mutations, we employed the allele-specific PCR and Sanger sequencing. MYD88 gene amplification and protein expression were analyzed by quantitative PCR and by immunohistochemistry, respectively. There were 17 cases of primary testicular DLBCL: 94% (16/17) exhibited a non-Germinal center B-cell (non-GCB) subtype, 82% (14/17) showed the MYD88 L265P, and 65% (11/17) had intense expression of MYD88. When compared with normal lymph nodes, the MYD88 is significantly amplified in primary testicular DLBCL. However, the amplification status showed no correlation with its mutational status or protein expression. Moreover, neither the MYD88 mutational status nor the expression pattern affected overall survival. Six cases were secondary testicular DLBCL with an 83% (5/6) and an 80% (4/5) incidence of the non-GCB subtype and of the MYD88 L265P, respectively. In conclusion, we demonstrated a high prevalence of the non-GCB subtype and the common MYD88 L265P in both primary and secondary testicular DLBCL. Our data suggest that the MYD88 mutation is a fairly consistent genetic feature in testicular DLBCL.

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

Background.

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

Patients and methods.

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

Results.

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

Conclusions.

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

Neuro-oncological disorders of the cerebellum

This article provides an overview of the intra-axial tumors that affect the cerebellum, which can be categorized by location and age. For each tumor, we review conventional neuroimaging findings and discuss the value of more advanced neuroimaging techniques. Current management strategies are also briefly discussed. Finally, cerebellar paraneoplastic disorders and medication-induced cerebellar disorders are discussed.

Imaging of brain tumors

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

Impact of therapeutic regimen and clinical presentation on overall survival in CNS lymphoma

BACKGROUND

The authors present a retrospective analysis of 45 patients who underwent treatment of CNS lymphoma (both primary and secondary) at a single institution between 2005 and 2012.

METHODS

This study involves 21 female and 24 male patients with a mean age of 59.2 years. All medical records and pathology reports were reviewed for each patient. Univariate and multivariate analyses of overall survival were performed.

RESULTS

Presentation with altered mental status was a significant risk factor for worse overall survival. An HIV infection, deep lesion location, and age over 60 did not impact survival. A survival benefit was demonstrated with the use of systemic therapy, specifically rituximab, and radiation. The CNS Lymphoma Score was derived from this cohort, which proved a powerful predictive tool for overall survival. The surgical complication rate in this series was 17.8 %.

CONCLUSIONS

This study highlights the prognostic importance of presenting mental status on outcomes in CNS lymphoma and demonstrates a summative benefit of rituximab and whole brain radiation therapy. Considering these factors together provides an easily applicable and meaningful stratification for this patient population. The surgical complication rate in this patient population is not negligible. The high percentage of wound-related surgical complications suggests the need for a waiting period between surgery and initiation of chemotherapy to allow for wound healing.

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

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

High prevalence of oncogenic MYD88 and CD79B mutations in diffuse large B-cell lymphomas presenting at immune-privileged sites

Activating mutations in CD79 and MYD88 have recently been found in a subset of diffuse large B-cell lymphoma (DLBCL), identifying B-cell receptor and MYD88 signalling as potential therapeutic targets for personalized treatment. Here, we report the prevalence of CD79B and MYD88 mutations and their relation to established clinical, phenotypic and molecular parameters in a large panel of DLBCLs. We show that these mutations often coexist and demonstrate that their presence is almost mutually exclusive with translocations of BCL2, BCL6 and cMYC, or Epstein–Bar virus infection. Intriguingly, MYD88 mutations were by far most prevalent in immune-privileged site-associated DLBCL (IP-DLBCL), presenting in central nervous system (75%) or testis (71%) and relatively uncommon in nodal (17%) and gastrointestinal tract lymphomas (11%). Our results suggest that MYD88 and CD79B mutations are important drivers of IP-DLBCLs and endow lymphoma-initiating cells with tissue-specific homing properties or a growth advantage in these barrier-protected tissues.

Combined diffusion and perfusion MR imaging as biomarkers of prognosis in immunocompetent patients with primary central nervous system lymphoma

BACKGROUND AND PURPOSE

ADC derived from DWI has been shown to correlate with PFS and OS in immunocompetent patients with PCNSL. The purpose of our study was to confirm the validity of ADC measurements as a prognostic biomarker and to determine whether rCBV measurements derived from DSC perfusion MR imaging provide prognostic information.

MATERIALS AND METHODS

Pretherapy baseline DWI and DSC perfusion MR imaging in 25 patients with PCNSL was analyzed before methotrexate-based induction chemotherapy. Contrast-enhancing tumor was segmented and coregistered with ADC and rCBV maps, and mean and minimum values were measured. Patients were separated into high or low ADC groups on the basis of previously published threshold values of ADC(min) < 384 × 10(-6) mm(2)/s. High and low rCBV groups were defined on the basis of receiver operating curve analysis. High and low ADC and rCBV groups were analyzed independently and in combination. Multivariate Cox survival analysis was performed.

RESULTS

Patients with ADC(min) values < 384 × 10(-6) mm(2)/s or rCBV(mean) values < 1.43 had worse PFS and OS. The patient cohort with combined low ADC(min)-low rCBV(mean) had the worst prognosis. No other variables besides ADC and rCBV significantly affected survival.

CONCLUSIONS

Our study reinforces the validity of ADC values as a prognostic biomarker and provides the first evidence of low tumor rCBV as a novel risk factor for adverse prognosis in immunocompetent patients with PCNSL.

Conservative management of post-transplant central nervous system lymphoma

Primary CNS lymphoma (PCNSL) is a rare B cell variant non-Hodgkins lymphoma that is confined to the brain, leptomeninges, spinal cord and eyes. Its incidence is increasing, primarily due to increase in the number of organ transplantations being undertaken. The majority of the PTLD (post-transplant lymphoproliferative disorder) is seen in kidney transplant recipients simply because they constitute a larger group of transplant recipients each year as compared to other solid organ transplantations. Primary infection of previously infected EBV seronegative patients and immunosuppression are found to be the main etiologic factors in the development of PTLD-PCNSL. There are no clear guidelines on treatment regimens, and it should be individualized according to patient comorbidities. We report a case of PCNS lymphoproliferative disorder in a kidney transplant recipient, which underwent complete remission with decreasing immunosuppression. The patient could not undergo chemotherapy/radiotherapy due to underlying comorbidities. We highlight the available treatment modalities for PTLD-PCNSL.

Aquaporin-4 expression in primary human central nervous system lymphomas correlates with tumour cell proliferation and phenotypic heterogeneity of the vessel wall

No literature data are available concerning the expression of aquaporin-4 in primary central nervous system lymphomas and the relationship between aquaporin-4 expression and the morphological characteristics of blood vessels. Here, we have investigated this relationship in 24 human diffuse large B-cell primary central nervous system lymphomas by means of immunocytochemistry and confocal laser microscopy. Results have shown that: (i) a high aquaporin-4 expression correlated with a high Ki-67 index and aquaporin-4 marked tumour and endothelial cells in cytoplasm and plasma membranes, while aquaporin-4 expression was low in tumour areas with a low Ki-67 index where few tumour cells were positive to aquaporin-4, and endothelial cells showed aquaporin-4 expression on their abluminal side. (ii) Different type of cells participated in vessels formation: CD20(+) tumour cells and factor VIII(+) endothelial cells; aquaporin-4(+) tumour cells and CD31(+) endothelial cells; CD20(+) and aquaporin-4(+) tumour cells; glial fibrillary acidid protein(+) endothelial cells surrounded by glial fibrillary acidic protein(+) tumour cells. Overall, these data suggest the importance of aquaporin-4 in primary central nervous system lymphomas due to its involvement in cerebral oedema formation and resolution and tumour cell migratory activity, and have documented that tumour microvasculature in lymphomas is extremely heterogeneous, confirming the importance of neoangiogenesis in the pathogenesis of lymphomas.

Ocular involvement in patients with primary CNS lymphoma

To describe the demographics, clinical characteristics, and treatment outcomes in patients with primary CNS lymphoma (PCNSL) with ocular involvement. A retrospective chart review was conducted on 61 patients who were diagnosed with PCNSL from January 2000 to October 2008 at the Asan Medical Center, Seoul, Korea. Among 46 patients who underwent ophthalmologic examination, 13 (28%) showed intraocular involvement. Mean age at diagnosis was 52.8 years, and 54% of patients were female. Diagnosis of PCNSL was made by vitrectomy (1 patient) or brain biopsy and/or CSF cytology (12 patients). In 4 (31%) patients, ocular symptoms preceded CNS symptoms. The most common ocular symptom was decreased visual acuity. Nine patients showed bilateral involvement. Intraocular findings included retinal infiltrative lesions (3 eyes), vitritis/vitreous opacity (5 eyes), or both (14 eyes). In addition to systemic chemotherapy and/or radiotherapy, vitrectomy and/or intravitreal methotrexate was utilized in 8 patients. Mean survival duration was 32.2 months (range 2-120 months). Although rare, the number of patients with PCNSL seems to be increasing in Korea. Early detection and dedicated treatment of intraocular lymphoma may result in improved visual outcome.

Central nervous system lymphoma: characteristic findings on traditional and advanced imaging

CNS lymphoma consists of 2 major subtypes: secondary CNS involvement by systemic lymphoma and PCNSL. Contrast-enhanced MR imaging is the method of choice for detecting CNS lymphoma. In leptomeningeal CNS lymphoma, representing two-thirds of secondary CNS lymphomas, imaging typically shows leptomeningeal, subependymal, dural, or cranial nerve enhancement. Single or multiple periventricular and/or superficial contrast-enhancing lesions are characteristic of parenchymal CNS lymphoma, representing one-third of secondary CNS lymphomas and almost 100% of PCNSLs. New CT and MR imaging techniques and metabolic imaging have demonstrated characteristic findings in CNS lymphoma, aiding in its differentiation from other CNS lesions. Advanced imaging techniques may, in the future, substantially improve the diagnostic accuracy of imaging, ultimately facilitating a noninvasive method of diagnosis. Furthermore, these imaging techniques may play a pivotal role in planning targeted therapies, prognostication, and monitoring treatment response.

Primary central nervous system lymphoma

There is no class I evidence for any therapeutic option in primary central nervous system lymphoma (PCNSL). When possible, patients should be included in clinical trials. The role of surgery is restricted to stereotactic biopsy in order to gain material for histopathologic diagnosis. Radiotherapy alone is associated with a median survival of no more than 1.5 years; cure is exceptional. However, in patients aged younger than 60 years, cure is the therapeutic aim. Polychemotherapy based on high-dose methotrexate with deferred radiation results in long-term survival in most of these patients and possibly cure in a substantial fraction of these patients. With regard to chemotherapy in PCNSL, the following must be considered: 1) the most efficient drug in PCNSL is methotrexate at a dosage of at least 1.5 g/m(2) per single dose; 2) methotrexate alone will lead to complete remission in only some patients, whereas the combination of methotrexate with other drugs is more efficient; and 3) the value of additional intraventricular chemotherapy and the necessity of "consolidation" radiotherapy after response to chemotherapy are not yet defined. For patients aged older than 60 years, no curative regimen with acceptable toxicity has yet been established. The combination of radiotherapy with methotrexate-based chemotherapy leads to severe long-term neurotoxic sequelae, ie, cognitive dysfunction, in most older patients and in some patients aged younger than 60 years.

Diffuse Large B-Cell Lymphoma—More Than a Diffuse Collection of Large B Cells: An Entity in Search of a Meaningful Classification

Context.—Diffuse large B-cell lymphoma is a heterogenous group of lymphomas. In this review, we present a brief description of the large number of entities recognized in the recently published (2008) World Health Organization classification of tumors of hematopoietic and lymphoid tissues.

Objective.—We highlight the unique clinicopathologic and molecular genetic features of these new and previously recognized entities, to illustrate the rational for the development of this classification. To help simplify the understanding of this now large and complex group of diseases, we have attempted to create broader subgroups of related entities. We discuss large B-cell lymphoma that are not otherwise specified, those that are based on anatomic site, those that have unique histology or phenotype or genotype, those that are associated with Epstein-Barr virus or Kaposi sarcoma–associated herpesvirus and herpesvirus 8, and those that are unclassifiable.

Data Sources.—World Health Organization classification of tumors of hematopoietic and lymphoid tissues (2008), published literature from PubMed (National Library of Medicine), and primary material from the authors' institution were reviewed.

Conclusions.—Recognition of the different subtypes of diffuse large B-cell lymphoma as described in the World Health Organization classification scheme will lead to improved understanding of the unique clinicopathologic and genetic features associated with these subtypes of lymphoma.

Chromosomal imbalances and partial uniparental disomies in primary central nervous system lymphoma

To determine the pattern of genetic alterations in primary central nervous system lymphomas (PCNSL), 19 PCNSL were studied by high-density single-nucleotide polymorphism arrays. Recurrent losses involved 6p21.32, 6q21, 8q12-12.2, 9p21.3, 3p14.2, 4q35.2, 10q23.21 and 12p13.2, whereas gains involved 18q21-23, 19q13.31, 19q13.43 and the entire chromosomes X and 12. Partial uniparental disomies (pUPDs) were identified in 6p and 9p21.3. These genomic alterations affected the HLA locus, the CDKN2A/p16, CDKN2B/p15 and MTAP, as well as the PRDM1, FAS, MALT1, and BCL2 genes. Increased methylation values of the CDKN2A/p16 promoter region were detected in 75% (6/8) PCNSL. Gene expression profiling showed 4/21 (20%) minimal common regions of imbalances to be associated with a differential mRNA expression affecting the FAS, STAT6, CD27, ARHGEF6 and SEPT6 genes. Collectively, this study unraveled novel genomic imbalances and pUPD with a high resolution in PCNSL and identified target genes of potential relevance in the pathogenesis of this lymphoma entity.

Primary central nervous system lymphoma: tumor-related clones exist in the blood and bone marrow with evidence for separate development

Primary central nervous system (CNS) lymphoma is an aggressive B-cell tumor that is defined clinically by the absence of systemic disease. We have used immunoglobulin variable (V)-gene analysis to identify tumor cells at the CNS site in 12 cases and to probe the involvement of peripheral tissues in 3 patients. Clonal tracking revealed tumor cells in the bone marrow and/or blood for 3 of 3 cases, with evidence for increased V-gene mutational activity at peripheral sites. In 2 of 3 cases, intraclonal variant analysis revealed identity with the brain biopsy but detected additional variants unique to extracerebral sites. These findings suggest that peripheral tumor cells can undergo separate development locally with no reentry into the brain. Primary CNS lymphoma appears to have both CNS-specific and systemic components with limited interchange. The more malignant behavior of tumor cells in the CNS suggests either a local environmental influence or a less malignant phenotype of the peripheral clone.

Recurrent inactivation of the PRDM1 gene in primary central nervous system lymphoma

Primary lymphomas of the CNS (PCNSLs) show molecular features of the late germinal center exit B-cell phenotype and are impaired in their terminal differentiation as indicated by a lack of immunoglobulin class switching. Because the positive regulatory domain I protein with ZNF domain (PRDM1/BLIMP1) is a master regulator of terminal B-cell differentiation into plasma cells, we investigated a series of 21 PCNSLs for the presence of mutations in the PRDM1 gene and alterations in the expression pattern of the PRDM1 protein. Direct sequencing of all coding exons of the PRDM1 gene identified deleterious mutations associated with abrogation of PRDM1 protein expression in 4 of 21 (19%) PCNSLs. Thus, similar to systemic diffuse large B-cell lymphomas, PRDM1 may be a tumor suppressor in some PCNSL and contribute to lymphomagenesis by impairing terminal differentiation.

Primary testicular diffuse large B-cell lymphomas have activated B-cell-like subtype characteristics

Diffuse large B-cell lymphomas (DLBCLs) constitute a heterogeneous group of lymphomas in which germinal centre B-cell-like and activated B-cell-like subtypes can be discerned based on pathology, clinical presentation, and gene expression patterns. Testicular DLBCLs form an immune-privileged site-related subgroup of DLBCLs with an unfavourable prognosis. In the present study, cDNA microarray analysis, immunohistochemistry for CD10, Bcl6 and MUM1, and somatic hypermutation analysis of the immunoglobulin heavy chain gene rearrangements were used to determine the subtype of primary testicular DLBCL. Immunohistochemistry revealed 14/22 testicular DLBCLs with an activated B-cell-like immunophenotype and 8/22 with an ambiguous immunophenotype co-expressing CD10 and high levels of MUM1. cDNA microarray analysis of these 22 and four additional cases showed a uniform activated B-cell-like gene expression pattern for both immunophenotypes. Somatic hypermutation analysis of immunoglobulin heavy chain genes showed a very high mutation load in seven cases tested, but intraclonal heterogeneity was found at low level in only one of these cases. It is concluded that primary testicular DLBCLs have uniform activated B-cell-like subtype characteristics despite a number of cases showing an ambiguous immunophenotype.

Expression pattern and cellular sources of chemokines in primary central nervous system lymphoma

The expression pattern of a subset of chemokines and their corresponding receptors was investigated in primary central nervous system lymphomas (PCNSL). The tumor cells consistently expressed CXCR4, CXCL12, CXCR5, and CXCL13, both at mRNA and protein levels. Cerebral endothelial cells were positive for CXCL12 and CXCL13, while reactive astrocytes and microglial cells expressed CXCL12, CCR5, and CCR6. Inflammatory T cells in PCNSL were characterized by CCR5 and CCR6 positivity. Taken together, our data indicate a cell type-specific repertoire of chemokine and chemokine receptor expression in PCNSL suggesting that chemokine-mediated interactions facilitate crossing of the blood-brain barrier as well as intracerebral dissemination of PCNSL cells. In addition, chemokines expressed by tumor cells may contribute to induction of reactive glial changes and influence the composition of inflammatory infiltrates in PCNSL. Therefore, cell type specific expression of distinct chemokine profiles likely plays a role in the pathogenesis of PCNSL and may contribute to their characteristic histological appearance.

[Primary CNS lymphoma in azathioprine therapy for autoimmune diseases: review of the literature and case report]

We present a 31-year-old female patient with primary non-Hodgkin's lymphoma of the CNS after immunosuppressive therapy. Colitis ulcerosa had been diagnosed 2 years previously. Prophylactic therapy with azathioprine over 9 months was stopped after the development of listeria meningitis which was treated successfully with antibiotics. At this time native CCT was normal. Three months later the patient developed an epileptic seizure and multiple cerebral lesions were detected in CCT and MRI. Although antibiotic therapy was started, the cerebral lesions showed no regression. Stereotactic biopsy revealed immunochemical and histologic high-grade malignant B cell lymphoma. The risk of primary CNS lymphoma under azathioprine treatment for an autoimmune disease with a possible congenital immunodeficiency is presented and the literature is reviewed.