Primary central nervous system lymphomas:

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.

Chemotherapy and the pediatric brain

Survival rates of children with cancer are steadily increasing. This urges our attention to neurocognitive and psychiatric outcomes, as these can markedly influence the quality of life of these children. Neurobehavioral morbidity in childhood cancer survivors affects diverse aspects of cognitive function, which can include attention, memory, processing speed, intellect, academic achievement, and emotional health. Reasons for neurobehavioral morbidity are multiple with one major contributor being chemotherapy-induced central nervous system (CNS) toxicity. Clinical studies investigating the effects of chemotherapy on the CNS in children with cancer have reported causative associations with the development of leukoencephalopathies as well as smaller regional grey and white matter volumes, which have been found to correlate with neurocognitive deficits.Preclinical work has provided compelling evidence that chemotherapy drugs are potent neuro- and gliotoxins in vitro and in vivo and can cause brain injury via excitotoxic and apoptotic mechanisms. Furthermore, chemotherapy triggers DNA (deoxyribonucleic acid) damage directly or through increased oxidative stress. It can shorten telomeres and accelerate cell aging, cause cytokine deregulation, inhibit hippocampal neurogenesis, and reduce brain vascularization and blood flow. These mechanisms, when allowed to operate on the developing brain of a child, have high potential to not only cause brain injury, but also alter crucial developmental events, such as myelination, synaptogenesis, neurogenesis, cortical thinning, and formation of neuronal networks.This short review summarizes key publications describing neurotoxicity of chemotherapy in pediatric cancers and potential underlying pathomechanisms.

Primary central nervous system lymphoma in a rheumatoid arthritis patient treated with methotrexate: a case report

Background

Rheumatoid arthritis is a systemic inflammatory disease characterized by synovitis and the destruction of articular structures in multiple joints. Methotrexate is recommended as an anchor drug for rheumatoid arthritis treatment to achieve the therapeutic goal of reducing damage to joints and improving clinical score. However, several studies have shown that methotrexate has been associated with the development of lymphoproliferative disorders, namely methotrexate-associated lymphoproliferative disorders. On the other hand, primary central nervous system lymphoma is an aggressive disease with poor prognosis. Both methotrexate-associated lymphoproliferative disorders and primary central nervous system lymphoma are reported to be associated with Epstein-Barr virus.

Case presentation

A Japanese female patient of between 60 and 70 years of age with rheumatoid arthritis was admitted to our hospital because of sudden convulsion and impaired consciousness. Just before admission, she was treated with adalimumab and methotrexate. Contrast-enhanced computed tomography scan showed a densely stained mass with surrounding edema in both frontal lobes and the left nucleus basalis, and enlarged lymph nodes in the right supraclavicular fossa. We performed a biopsy of the right cervical lymph node, but could not establish a histopathological diagnosis. In situ hybridization showed the presence of Epstein Barr virus, therefore we diagnosed this case as methotrexate-associated lymphoproliferative disorders mediated by Epstein Barr virus after considering the drug history of the patient. After we discontinued methotrexate, patient symptoms gradually improved. The masses at both frontal lobes and the left nucleus basalis were gradually regressed.

Conclusion

Since the frequency of methotrexate use and the maximum dosage has been increasing, particular attention should be paid to the development of methotrexate-associated lymphoproliferative disorders in rheumatoid arthritis patients who are treated with methotrexate.

Disseminated encephalomyelitis-like central nervous system neoplasm in childhood

A malignant neoplasm in the central nervous system with diffuse white matter changes on magnetic resonance imaging (MRI) is rare in children. It could be misdiagnosed as acute disseminated encephalomyelitis. This report presents our experience based on 4 patients (3 male, 1 female; aged 7-13 years) whose MRI showed diffuse lesions in white matter and who were initially diagnosed with acute disseminated encephalomyelitis. All of the patients received corticosteroid therapy. After brain biopsy, the patients were diagnosed with gliomatosis cerebri, primitive neuroectodermal tumor and central nervous system lymphoma. We also provide literature reviews and discuss the differentiation of central nervous system neoplasm from acute disseminated encephalomyelitis.

Epstein-Barr virus and methotrexate-related CNS lymphoma in a patient with rheumatoid arthritis

Patients with rheumatoid arthritis (RA), especially those treated with methotrexate (MTX), might have an increased risk of lymphoproliferative disorders that are associated with Epstein-Barr virus (EBV). We describe a case of EBV-associated central nervous system (CNS) lymphoma (diffuse large B-cell lymphoma) in a patient with RA on a short course of MTX treatment. The neoplastic cells express the B-cell surface markers (CD20, Pax-5 and CD30), and EBV-encoded RNA was demonstrated by in situ hybridization. The patient's lymphoma did not recur for the 8-year follow-up period after the tumor resection and cessation of MTX. MTX may promote EBV-positive CNS lymphoma in RA patient due to its immunosuppressive properties as well as reactivating latent EBV infection.

Primary central nervous system lymphoma

INTRODUCTION

Primary central nervous system lymphoma is a rare subtype of extranodal non-Hodgkin lymphoma that accounts for 4% of central nervous system tumours.

PATIENTS AND METHODS

Retrospective review of 24 patients diagnosed with primary central nervous system lymphoma between 1990 and 2010. All patients were diagnosed using magnetic resonance imaging and the diagnosis was confirmed surgically.

RESULTS

Of the 24 patients analysed, all except 4 were immunocompetent. Median age at diagnosis was 59.3 years (range 13-79) and the sex ratio (male to female) was 1:1.1. Cognitive decline (in 33.4%) and headache (in 25%) were the most common complaints. Diagnosis was performed In 13 cases (54%) following craniotomy and in the other 11 cases (46%) after stereotactic biopsy. Breakdown by pathology was as follows: 22 cases of B-cell lymphoma (91.6%), 1 case of anaplastic large-cell lymphoma, and 1 case of T-cell lymphoma. Mean survival time was 12.8 months with an overall 1-year survival rate of 37.5%.

CONCLUSIONS

Primary central nervous system lymphoma often presents in the sixth decade with cognitive decline, headache, and focal neurological deficits. A single intracranial lesion was present in 75% of the patients (18 cases), and the remaining 25% (6 cases) had between 2 and 4 lesions. Preoperative clinical status was the most important factor determining prognosis.

Primary central nervous system lymphoma in immunocompetent patients: a retrospective review of MRI features

INTRODUCTION

To define the features of primary central nervous system lymphoma (PCNSL) on MRI in immunocompetent patients.

METHODS

A retrospective review of the authors' institutional database was performed to identify histologically proven cases of PCNSL. Images were retrieved and reviewed with respect to location, lesion number, size, signal intensity, enhancement characteristics, oedema and necrosis.

RESULTS

Thirty-one cases of histologically proven PCNSL had available imaging. One patient was excluded due to immunosuppression. Of the 30 remaining cases, the average age was 65.5 years, and males and females were equally represented. A total of 68 lesions (average of 2.5 per patient) were identified. With diffusion-weighted imaging, all but two had restricted diffusion (40.3% mild and 55.6% marked) and all but one had enhancement (51.5% homogeneous, 42.6% heterogeneous and ring 4.4%). Most lesions were isointense to grey matter (75.8% on T2-weighted image (WI) and 82.5% on T1-WI). Oedema was mild in 43.4% and marked in 55.2%. Necrosis was seen in only five lesions (7.4%). On a per patient basis, 50% had bilateral lesions and 96.7% had lesions contacting a cerebrospinal fluid (CSF) surface. 16.7% of patients had posterior fossa involvement and 30% had lesions in the basal ganglia or thalami.

CONCLUSION

The vast majority of cases of PCNSL in immunocompetent patients have lesions contacting a CSF surface, enhancement and restricted diffusion with no necrosis. These features should alert radiologists to the diagnosis of PCNSL.

Lymphomatosis cerebri presenting as a rapidly progressive dementia with a high methylmalonic acid

We report a case of a patient with a rapidly progressive dementing illness and gait disturbance, in whom initial screening demonstrated a high methylmalonic acid level only, suggestive of a functional vitamin B(12) deficiency. Despite B(12) replacement therapy, he continued to decline. Further investigations demonstrated extensive signal change on magnetic resonance imaging involving grey and white matter within the corpus callosum, deep grey matter, brainstem and cerebellar peduncles, and patchy post-contrast enhancement. Laboratory testing revealed a raised erythrocyte sedimentation rate, raised anti-nuclear, intrinsic factor and lupus anticoagulant antibody titres, and a IgG kappa paraprotein. Cerebrospinal fluid was unremarkable. Bone marrow trephine biopsy showed monoclonal gammopathy of unknown significance. The patient initially responded to steroids, and underwent a brain biopsy, which was uninformative. However, 3 weeks following admission, he died due to an aspiration pneumonia. Autopsy findings were consistent with a diffuse primary central nervous system small cell B-cell lymphoma. This has been rarely reported in the medical literature, but our case exhibits typical clinical features, although patchy enhancement on imaging and the high methylmalonic acid have not been previously described. We hypothesise that his functional B(12) deficiency may have resulted from rapid cell turnover, perhaps in conjunction with the presence of intrinsic factor antibodies.

Diffuse large B-cell lymphoma of the central nervous system in mycophenolate mofetil-treated patients with systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) are susceptible to the development of lymphoproliferative disorders and postulated causes include intrinsic defects in immune surveillance and iatrogenic administration of immunosuppressants. Since the introduction of mycophenolate mofetil (MMF) to the immunosuppressive regimen for the management of post-organ transplantation, there have been reports of primary lymphoma of the central nervous system (PCNSL). MMF has been widely used to treat active SLE patients with Class IV lupus nephritis. In addition to two previously reported cases of PCNSL among SLE patients on long-term MMF, we report a third patient who has been on treatment with MMF for 8 years. The histology showed features compatible with diffuse large B-cell lymphoma with strong immunohistochemical staining for CD20 and positive signal for Epstein-Barr virus (EBV)-encoded RNA by in-situ hybridization that is similar to other case reports, suggesting EBV driven B-cell lymphoproliferative disease. The patient responded to withdrawal of MMF, intravenous methotrexate, rituximab and whole brain radiotherapy. With the increasing use of MMF in active renal as well as non-renal exacerbations of SLE, PCNSL should be included in the differential diagnosis in patients who present with gradual onset of focal neurological deficit.

[Therapeutic management of central nervous system lymphomas in a single hematological institute]

Primary central nervous system lymphoma is defined as an extranodal lymphoma arising in the central nervous system in the absence of systemic disease. Because of their rare occurrence among lymphomas, optimal treatment could hardly be established.

AIMS

In this retrospective survey we analyzed the result of combined treatment (systemic and intrathecal chemotherapy followed by consolidation radiotherapy) in patients with primary or relapsed central nervous system lymphomas diagnosed and treated in our hematological department between 1998-2009.

PATIENTS AND METHODS

During this period (mean follow-up of 13.2 months) from 427 patients with newly diagnosed non-Hodgkin's lymphomas, 22 primary central nervous system lymphoma was diagnosed (5.15%, 16 cerebral and 6 spinal cord lymphoma cases). Significant male predominance (14:8) was registered with an age distribution of 34-77 years (mean = 60.7, median = 64 years). No patients were immunocompromised. All central nervous system lymphoma specimens taken with neurosurgical resection or stereotaxic biopsies were confirmed histopathologically. All cerebral lymphoma cases proved to be diffuse large B-cell of origin, while in epidural lymphomas low grade subtypes also occurred. Epidural lymphomas were treated with local radiotherapy (30-40 Gy), except for patients with follicular lymphomas getting rituximab-containing polychemotherapy (R + CHOP regimen) before irradiation. In cerebral lymphoma (every patients had supratentorial localization) the following combined therapy protocol was used: up to three courses of high dose methotrexate (HD MTX 3g/m 2 in a single dose for 4 hours lasting drop-infusion) were given at 4-week intervals, followed by leucovorin-rescue 24 hours after MTX infusion. Intrathecal combination of methotrexate, cytosin-arabinosid and dexamethasone was given three times after HD MTX infusion. In complete response after chemotherapy (evaluated by cranial MRI or CT, PET/CT), whole-brain irradiation was used in a total dose of 30 Gy. In case of partial response, boost irradiation for the tumor bed was also given. In relapse or resistant cases, salvage regimen was applied: HD MTX course combined with high dose cytosin-arabinosid (HD Ara-C) 3g/m 2 /dose b.i.d. over 4 h c.i., repeated in three cycles every four weeks.

RESULTS

Complete remission has been achieved in 9 patients with cerebral and in 4 patients with spinal cord lymphoma (13/22; 59.0%), however, one relapsed patient became resistant and later expired, despite salvage therapy. Primarily 9 patients were not evaluable for response: 5 received only one or two HD MTX because of side effects, 4 patients died due to progression of the disease. Mean of the overall survival (OS) in cerebral lymphoma was 19.5 (3-46, median of 10) months, in epidural group 14.1 (2-76, median of 5) months, whilst mean time to progression (TTP) was 4.5 (2-6.5, median of 4 months). The 2-year survival for all patients was 50%. Acute toxicity of chemotherapy was usually hematological, moreover, in 8 patients impaired renal function and sepsis developed. No serious adverse effect of radiotherapy could be detected.

CONCLUSION

In primary central nervous system lymphoma, basic treatment HD methotrexate together with intrathecal combination of methotrexate + cytosin-arabinosid + dexamethasone followed by whole-brain irradiation of at least 30 Gy could produce a medium response rate in our study. In case of relapse or progression, other salvage regimens containing HD Ara-C alternating with HD MTX could reduce the treatment failure, as well. After therapy PET/CT was negative in five patients with prolonged disease-free survival.

Epstein Barr virus-associated primary CNS lymphomas in elderly patients on immunosuppressive medications

Unlike primary central nervous system lymphomas (PCNSLs) in patients with AIDS or organ transplants, PCNSLs in the elderly are usually not considered to be mediated by Epstein Barr virus (EBV); hence, diagnostic studies for EBV are not routinely performed. We encountered 4 patients, 65 years or older, who developed EBV-associated PCNSLs and who had been treated with a variety of immunosuppressive drugs for different autoimmune/collagen vascular disorders, including autoimmune polyneuropathy (mycophenolate mofetil for 5 years), polymyositis (prednisone for 16 years with intermittent methotrexate, azathioprine, and cyclophosphamide), myasthenia gravis (azathioprine >10 years), and rheumatoid arthritis (methotrexate >10 years). All patients had multifocal, necrotic brain lesions typical of EBV-positive PCNSLs on neuroimaging. Withdrawing immunosuppressives lead to PCNSL regression in some patients. The patient who had received mycophenolate mofetil was treated successfully for his EBV-associated PCNSL with rituximab and methotrexate, but later developed fatal systemic malignant melanoma, which was likely immunosuppression related. The striking feature of these cases is the variety of underlying diseases-and hence accompanying medications-that can be associated with EBV-associated PCNSLs. They serve as a diagnostic alert for neuropathologists and suggest that increased testing of PCNSLs for EBV by immunohistochemistry or in situ hybridization may be warranted in any patient on any immunosuppressive medication, but particularly the elderly.

Primary central nervous system lymphoma with intraocular recurrence after optic nerve disorder

PURPOSE

To describe a patient with primary central nervous system lymphoma (PCNSL) who developed intraocular recurrence after the onset of optic nerve disorder.

METHODS

A 46-year-old woman developed bilateral central vision loss 1 year after the onset of PCNSL. Ophthalmologic examination, including perimetry, magnetic resonance imaging, and determination of visual evoked potential, was performed.

RESULTS

These examinations revealed a diagnosis of bilateral optic nerve disorder, and optic nerve disorder spontaneously resolved. Six months later, the patient had blurred vision in the left eye. Funduscopic examination revealed dense vitreous opacity and geographic subretinal exudates. Cytologic analysis of vitreous obtained by pars plana vitrectomy led to a diagnosis of recurrent intraocular lymphoma. The patient again developed brain recurrence 8 months after chemotherapy for intraocular recurrence.

CONCLUSION

The clinical course in this case suggests that lymphoma cells infiltrated from the brain into the eye along the optic nerve.

Distinguishing primary central nervous system lymphoma from other central nervous system diseases: a neurosurgical perspective on diagnostic dilemmas and approaches

OBJECT

White matter diseases, including demyelinating or inflammatory disorders, may be indistinguishable clinically and radiologically from some central nervous system (CNS) tumors. In such situations, determination of the final diagnosis is difficult. An example is the differential diagnosis of non-acquired immunodeficiency syndrome-related primary central nervous system lymphoma (PCNSL) and multiple sclerosis (MS), a demyelinating disease. Unfortunately, delayed diagnosis and treatment of PCNSL can negatively affect prognosis.

METHODS

The authors reviewed the cases of eight patients with PCNSL or MS. In each case, the initial diagnosis (PCNSL or MS) was equivocal. In these cases, conventional diagnostic approaches were not definitive, thus further delaying diagnosis. The initial symptoms, the selected diagnostic tests, and the presumptive as well as final diagnosis for each case are discussed. The final diagnosis was PCNSL in six cases and MS in two. The uncertainty about the clinical or initial pathological presentation required further diagnostic evaluation in all cases. Two important neurosurgical guidelines are the avoidance of corticosteroid agents and performance of biopsy sampling rather than volumetric tumor resection. Highvolume lumbar puncture, slit-lamp examination/vitrectomy, new CNS imaging techniques, and repeated biopsy procedures also proved helpful.

CONCLUSIONS

In PCNSL, early definitive diagnosis and treatment are the keys to successful outcomes. Knowledge of strategies essential to early diagnosis lessens the need for brain biopsy sampling, but this procedure is still usually necessary. In such selected cases, biopsy sampling is appropriate even when pathological investigation shows MS rather than PCNSL. Complete resection is not indicated in PCNSL and can lead to additional sequelae.

Cancer therapy-associated CNS neuropathology: an update and review of the literature

Standard therapeutic options for brain tumors include surgery, radiation, and chemotherapy. Unfortunately, these same therapies pose risks of neurotoxicity, the most common long-term complications being radiation necrosis, chemotherapy-associated leukoencephalopathy, and secondary neoplasms. These side effects remain difficult to predict, but are associated with risk factors that include patient age, therapeutic modality and dosage, genetic background, and idiosyncratic predispositions. Experimental treatments designed to enhance efficacy and to minimize neurotoxicity include molecularly targeted, genetic, stem cell, and immune therapies. Newer modifications in radiation and drug delivery include stereotactic radiosurgery, interstitial therapy such as intracavitary brachytherapy and gliadel wafer placement, 3D conformal radiation, boron neutron capture therapy, radiosensitizers, blood-brain barrier disrupting agents, and convection enhanced delivery. Toxicities associated with these newer modalities have yet to be fully investigated and documented. Additionally, a number of recently implemented radiographic techniques such as PET and SPECT imaging have enhanced the ability to distinguish recurrent tumor from radiation necrosis. Nevertheless, post-therapeutic brain biopsies and autopsies remain the gold standard for assessing neurotoxicity, therapeutic efficacy, tumor progression, and the development of secondary neoplasms. At the same time, treatment-associated changes such as tumor necrosis, vasculopathy, inflammation, and cytologic atypia can pose significant diagnostic pitfalls, particularly if the pathologist is not provided a detailed therapeutic history. Therefore, it is critical to recognize the full spectrum of cancer therapy-associated neuropathology, the topic of the current review.

HIV-associated retinopathy in the HAART era

BACKGROUND

The effectiveness of highly active antiretroviral therapy (HAART) in restoring immune function in patients with acquired immunodeficiency syndrome (AIDS) has led to changes in the incidence, natural history, management, and sequelae of human immunodeficiency virus (HIV)-associated retinopathies, especially cytomegalovirus (CMV) retinitis.

METHODS

The medical literature pertaining to HIV-associated retinopathies was reviewed with special attention to the differences in incidence, management strategies, and complications of these conditions in the eras both before and after the widespread use of HAART.

RESULTS

In the pre-HAART era, CMV retinitis was the most common HIV-associated retinopathy, occurring in 20%-40% of patients. Median time to progression was 47 to 104 days, mean survival after diagnosis was 6 to 10 months, and indefinite intravenous maintenance therapy was mandatory. Retinal detachment occurred in 24%-50% of patients annually. Herpetic retinopathy and toxoplasmosis retinochoroiditis occurred in 1%-3% of patients and Pneumocystis carinii choroiditis, syphilitic retinitis, tuberculous choroiditis, cryptococcal choroiditis, and intraocular lymphoma occurred infrequently. In the HAART era the incidence of CMV retinitis has declined 80% and survival after diagnosis has increased to over 1 year. Immune recovery in patients on HAART has allowed safe discontinuation of maintenance therapy in patients with regressed CMV retinitis and other HIV-associated retinopathies. Immune recovery uveitis (IRU) is a HAART dependent inflammatory response that may occur in up to 63% of patients with regressed CMV retinitis and elevated CD4 counts and is associated with vision loss from epiretinal membrane, cataract, and cystoid macular edema.

CONCLUSIONS

The incidence, visual morbidity, and mortality of CMV retinitis and other HIV-associated retinopathies have decreased in the era of HAART and lifelong maintenance therapy may safely be discontinued in patients with restored immune function. Patients with regressed CMV retinitis, however, may still lose vision from epiretinal membrane, cystoid macular edema, and cataract secondary to IRU.

The serotonin transporter (SLC6A4) is present in B-cell clones of diverse malignant origin: probing a potential anti-tumor target for psychotropics

Following our previous description of the serotonin transporter (SERT) acting as a conduit to 5-hydroxytryptamine (5-HT)-mediated apoptosis, specifically in Burkitt's lymphoma, we now detail its expression among a broad spectrum of B cell malignancy, while exploring additional SERT substrates for potential therapeutic activity. SERT was readily detected in derived B cell lines with origins as diverse as B cell precursor acute lymphoblastic leukemia, mantle cell lymphoma, diffuse large B cell lymphoma, and multiple myeloma. Concentration and timecourse kinetics for the antiproliferative and proapoptotic activities of the amphetamine derivatives fenfluramine (an appetite suppressant) and 3,4-methylenedioxymethamphetamine (MDMA; "Ecstasy") revealed them as being similar to the endogenous indoleamine. A tricyclic antidepressant, clomipramine, instead mirrored the behavior of the selective serotonin reuptake inhibitor fluoxetine, both being effective in the low micromolar range. A majority of neoplastic clones were sensitive to one or more of the serotonergic compounds. Dysregulated bcl-2 expression, either by t(14;18)(q32;q21) translocation or its introduction as a constitutively active transgene, provided protection from proapoptotic but not antiproliferative outcomes. These data indicate a potential for SERT as a novel anti-tumor target for amphetamine analogs, while evidence is presented that the seemingly more promising antidepressants are likely impacting malignant B cells independently of the transporter itself.

Primary central nervous system lymphoma - A hospital based study of incidence and clinicopathological features from India (1983-2003)

Over the last two decades, an increase in the incidence of PCNSL cases has been reported in the West, both among immunosuppressed and immunocompetent patients. The present study was undertaken to assess the trend of incidence of PCNSL cases in India. To the best of our knowledge, only a single such report is available from India. All biopsy proven PCNSL cases obtained from the Neurosurgical databases of two large referral hospitals, one in Northern India (AIIMS, New Delhi) and another in Southern India (NIMHANS, Bangalore) from the period 1980 to 2003, were reviewed. Immunophenotyping was done and relevant clinical details collected. Appropriate statistical analysis was done to assess any change in trend of incidence or age at presentation. PCNSL cases constituted 0.95% and 0.92% of the total intracranial neoplasms at AIIMS and at NIMHANS, respectively. The mean age for cases diagnosed at AIIMS was 44.35 years, while that for NIMHANS was 39.51 years. Statistical analysis to evaluate any change in trend either of incidence or of age at presentation, over the study period, did not reveal any significant change. All the cases occurred in immunocompetent patients, except one case of HIV positive at NIMHANS, and one case of renal transplant at AIIMS. Frontal lobe was the most common site of involvement. Majority of the cases were diffuse, high grade, large cell lymphoma, B-cell immunophenotype. Thus, this multicentric hospital based study did not reveal any increase in incidence of PCNSL cases in India over the past 24 years. Further, in contrast to the West, majority of the cases in this Indian study were immunocompetent and a decade younger than in the West. The association of PCNSL with HIV/AIDS has been low in India, possibly due to early death in AIDS on account of opportunistic infections.