Occult systemic non-Hodgkin's lymphoma (NHL) in patients initially diagnosed as primary central nervous system lymphoma (PCNSL): how much staging is enough?

Bone marrow biopsy can be omitted in the diagnostic workup of CNS lymphoma of DLBCL origin: a population-based retrospective study in the PET-CT era

Currently, bone marrow (BM) biopsy (BMB) is recommended in the initial staging of patients with the presumed primary central nervous system (CNS) lymphoma (PCNSL). However, the added value of BMB in the era of positron emission tomography (PET-CT) has been challenged in other lymphoma subtypes. We analyzed BM findings in patients with biopsy-proven CNS lymphoma and a negative PET-CT scan for disease outside CNS. A comprehensive Danish population-based registry search was performed to identify all patients with CNS lymphoma of diffuse large B cell lymphoma (DLBCL) histology with available BMB results and staging PET-CT without systemic lymphoma. A total of 300 patients fulfilled the inclusion criteria. Of them, 16% had a previous history of lymphoma, while 84% were diagnosed with PCNSL. None of the patients had DLBCL in the BM. A minority (8.3%) had discordant BMB findings, mainly low-grade histologies that did not influence treatment choice in any case. In conclusion, the risk of overlooking concordant BM infiltration in patients with CNS lymphoma of DLBCL histology and negative PET-CT scan is negligible. As we did not find any patient with DLBCL in the BMB, our results suggest that BMB can be safely omitted in the diagnostic workup in patients with CNS lymphoma and a negative PET-CT.

Body CT and PET/CT Detection of Extracranial Lymphoma in Patients with Newly Diagnosed Central Nervous System Lymphoma

BACKGROUND

We aimed to investigate the detection rate of body CT or PET/CT for sites of extracranial disease in patients with a new pathological diagnosis of CNS DLBCL and to identify factors associated with sites of extracranial disease.

METHODS

An international multicenter cohort study of consecutive immunocompetent patients with a new diagnosis of CNS DLBCL confirmed by brain biopsy who underwent CT and/or PET/CT to evaluate for sites of extracranial disease between 1998 and 2019. The primary outcome was the detection rate of extracranial lymphoma by CT or PET/CT. Subgroup analyses according to age and EBV status were also performed. Logistic regression analyses were performed to determine factors related to sites of extracranial disease. Detection rates of CT and PET/CT were compared.

RESULTS

1043 patients were included. The overall detection rate of CT or PET/CT was 2.6% (27/1043). The treatment approach was adjusted in 74% of these patients. Multivariable analysis demonstrated that age>61-years (OR, 3.10; P=.016) and EBV positivity (OR, 3.78; P=.045) were associated with greater odds of extracranial lymphoma. There was no statistically significant difference in detection rate between CT and PET/CT (P=.802). In patients≤61 years old, the false-referral rates were significantly higher than the detection rates (P<.001).

CONCLUSION

Our results showed increased odds of extracranial lymphoma in patients with older age or EBV-positive lymphoma. Treatment was adjusted in a majority of patients diagnosed with extracranial lymphoma, thereby supporting the current guidelines for the use contrast-enhanced body CT or PET/CT in patients with newly diagnosed CNS DLBCL.

The value of bone marrow biopsy for staging of patients with primary CNS lymphoma

BACKGROUND

In patients with presumed primary CNS lymphoma (PCNSL) a systemic manifestation is found only in a small minority. Although bone marrow biopsy (BMB) is recommended for staging, its diagnostic value is unclear.

METHODS

A retrospective analysis of 392 patients with presumed PCNSL from three university hospitals and 33 patients with secondary CNS lymphoma (SCNSL) and initial CNS involvement from a multicentre Germany-wide prospective registry was performed.

RESULTS

A BMB was performed and documented in 320/392 patients with presumed PCNSL; 23 had pathologic results. One harboured the same lymphoma in the brain and bone marrow (BM), 22 showed findings in BM discordant to the histology of brain lymphoma; n=12 harboured a low grade lymphoma in the bone marrow, the other showed B-cell proliferation but no proof of lymphoma (n=5), monoclonal B-cells (n=3) or abnormalities not B-cell associated (n=2). In the group of SCNSL with initial CNS manifestation 32/33 patients underwent BMB; seven were documented with bone marrow involvement (BMI); one had concordant results in the brain and bone marrow with no other systemic manifestation. Six had additional systemic lymphoma manifestations apart from the brain and bone marrow.

CONCLUSIONS

In only two out of 352 (0.6%) patients with CNS lymphoma (320 presumed PCNSL and 32 SCNSL) BMB had an impact on diagnosis and treatment. While collected in a selected cohort these findings challenge the value of BMB as part of routine staging in presumed PCNSL.

Vitreoretinal Lymphoma: A Literature Review and Introduction of a New Diagnostic Method

PURPOSE

The aim of this study was to briefly review the clinical and diagnostic features of vitreoretinal lymphoma (VRL) and to introduce the recent introduction of metagenomic deep sequencing in this ocular lymphomatous disease.

DESIGN AND METHODS

Review and description of the process of using metagenomic deep sequencing for ocular specimens at the Proctor Foundation, University of California, San Francisco, CA.

RESULTS

VRL masquerades as a uveitis, but clinical signs of subretinal lesions, and vitritis should prompt the inclusion of VRL in a differential diagnosis. Imaging features such as hyporeflective infiltrative lesions between the retinal pigment epithelium and Bruch's membrane are compatible with VRL, but diagnosis requires satisfying specific cytopathological and immunohistochemical or molecular features. Diagnosis, then, is subject to the cellularity, viability, and volume of the specimen submitted for these tests. Metagenomic deep sequencing has the ability to detect numerous lymphoma-associated mutations and is able to utilize minute volume samples and cell-free nucleic acid, so is well-suited for ocular tissues.

CONCLUSIONS

Metagenomic deep sequencing may offer an additional tool in the future with which to diagnose VRL.

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.

Use of FDG-PET/CT for systemic assessment of suspected primary central nervous system lymphoma: a LOC study

INTRODUCTION

Primary Central Nervous System Lymphoma (PCNSL) is a rare disease with different therapeutic implications than systemic lymphoma. In this study, we evaluated whole-body ¹⁸FDG-PET/CT for pre-chemotherapy imaging of suspected PCNSL.

METHODS

One hundred and thirty consecutive immunocompetent patients were retrospectively included. The results of initial ¹⁸FDG-PET/CT, contrast-enhanced CT (CeCT) and bone marrow biopsy (BMB) when available were compared to a gold standard based on pathological diagnosis or follow-up.

RESULTS

CNS lesion pathology showed large B-cell lymphoma in 95% of patients, including 11 patients with primary vitro-retinal lymphoma. Ten patients (8%) where ultimately diagnosed with systemic lymphoma involvement, including five pathologically confirmed cases, all of which were detected by ¹⁸FDG-PET/CT. ¹⁸FDG-PET/CT showed incidental systemic findings unrelated to lymphoma in 14% of patients. An SUVmax threshold of nine enabled good discrimination between systemic lymphoma and other lesions (sensitivity 92% and specificity 89%). CeCT and BMB performed in 108 and 77 patients respectively revealed systemic lesions in only three patients.

CONCLUSION

¹⁸FDG-PET/CT detected concomitant occult systemic involvement in a non-negligible proportion of suspected PCNSL cases (8%). In this setting its sensitivity is higher than that of CeCT. All of our patients ultimately diagnosed with concomitant systemic involvement had positive ¹⁸FDG-PET/CT. We believe it constitutes a safe one-stop shop evaluation for the systemic pre-treatment imaging of suspected PCNSL.

Utility of flouro-deoxy-glucose positron emission tomography/computed tomography in the diagnostic and staging evaluation of patients with primary CNS lymphoma

Aim: To prospectively assess the clinical utility of pretreatment flouro-deoxy-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in patients with primary central nervous system (CNS) lymphoma (PCNSL). Materials & methods: Patients with suspected/proven PCNSL underwent baseline whole-body 18F-FDG-PET/CT. Maximum standardized uptake value and tumor/normal tissue ratios were compared between CNS lymphoma and other histological diagnoses. Results: The mean maximum standardized uptake value (27.5 vs 18.2; p = 0.001) and mean tumor/normal tissue ratio (2.34 vs 1.53; p < 0.001) of CNS lymphoma was significantly higher than other histologic diagnoses. Five of 50 (10%) patients with biopsy-proven CNS lymphomas had pathologically increased FDG-uptake at extraneuraxial sites uncovering systemic lymphoma. Conclusion: Pretreatment whole-body 18F-FDG-PET/CT provides valuable complementary information in the diagnostic and staging evaluation of patients with PCNSL to guide therapeutic decision-making.

Primary Central Nervous System Lymphoma: Diagnostic Yield of Whole-Body CT and FDG PET/CT for Initial Systemic Imaging

Background Updated guidelines for suspected primary central nervous system lymphoma (PCNSL) are lacking. Purpose To investigate the diagnostic yield of initial systemic imaging in patients suspected of having PCNSL by using contrast material-enhanced chest and abdominopelvic CT and/or whole-body fluorine 18 fluorodeoxyglucose (FDG) PET/CT. Materials and Methods This retrospective study included 304 patients examined at a single tertiary hospital between January 1998 and October 2018. Consecutive adults (age >18 years) who were confirmed to have newly diagnosed PCNSL on the basis of findings at stereotactic brain biopsy were recruited. All patients were examined with contrast-enhanced chest and abdominopelvic CT and/or whole-body FDG PET/CT before initiation of PCNSL treatment. The diagnostic yield of CT and PET/CT was determined before therapy and at the time of recurrence in the brain. A χ² test was performed to compare the diagnostic yield according to study date in order to assess for possible changes in technology during the study period. Results A total of 304 patients (180 men with a mean age [±standard deviation] of 58 years ± 13 and 124 women with a mean age of 59 years ± 13) were included. The diagnostic yield of CT and PET/CT for initial staging was 2% (six of 304 patients; 95% confidence interval [CI]: 0.7%, 4.3%), and these tests yielded false-positive findings in 13 of the 304 patients (4%; 95% CI: 2.3%, 7.2%). Diagnostic yield did not differ between patients evaluated before 2009 and those evaluated in 2009 and later (P = .82). The diagnostic yield of systemic imaging at recurrence was 1.5% (one of 68 patients; 95% CI: 0.0%, 7.9%), and these tests yielded false-positive findings in four of those 68 patients (6%; 95% CI: 1.6%, 14.4%). Conclusion Contrast-enhanced chest and abdominopelvic CT and/or whole-body fluorine 18 fluorodeoxyglucose PET/CT for initial staging, as well as for recurrence of suspected primary central nervous system lymphoma, had a low diagnostic yield. © RSNA, 2019 See also the editorial by Jara in this issue.

Non-Hodgkin Lymphoma With Longitudinally Extensive Transverse Myelopathy as the Initial Symptom: A Case Report

Identifying lymphoma as the cause of neurological disease is diagnostically challenging when the clinical manifestations are atypical. We report an unusual case of a previously healthy immunocompetent 67-years-old man presenting with acute onset of symptoms of myelopathy and mild personality changes. Magnetic resonance imaging (MRI) revealed multifocal periventricular lesions and longitudinally extensive transverse myelitis (LETM). He had very good response to corticosteroids and was in remission for over 6 months. Repeat MRI showed an unexpected mass lesion in the brain which was later confirmed by brain biopsy as diffuse large B cell lymphoma. Subsequent FDG-PET/CT revealed systemic disease with lymphonodal and testicular manifestations (Stage IV disease). It is therefore important to consider lymphoma as a differential diagnosis in patients with LETM and demyelinating lesions in the brain.

Staging identifies non-CNS malignancies in a large cohort with newly diagnosed lymphomatous brain lesions

Lymphomatous brain lesions can represent primary central nervous system (CNS) lymphoma or secondary involvement as part of systemic disease (SCNSL). In this study, we characterize staging evaluations in a large patient cohort with newly-diagnosed brain lymphomas, to determine the frequency of SCNSL and secondary malignancies. This retrospective review includes 262 patients with newly-diagnosed lymphomatous CNS lesions evaluated at Memorial Sloan Kettering Cancer Center between 2006 and 2018. Staging procedures included PET scans in 180 (69%) patients, CT scans of chest/abdomen/pelvis (CAP) in 195 (74%) and bone marrow biopsies (BMB) in 177 (68%). PET scans were reported as abnormal in 34 of 180 (19%), CT in 50 of 195 (26%) and BMB in 15 of 177 (8.5%). A total of 24 non-CNS malignancies were identified (11.8%; 19 systemic lymphomas and 5 secondary malignancies). Thus, in patients with new lymphomatous brain lesions, performing initial systemic staging procedures can identify systemic lymphoma and additional malignancies, highlighting the importance of staging evaluations, in particular PET and BMB.

18F-FDG PET/CT in primary brain lymphoma

The actual role of 18F-FDG PET/CT in evaluating primary brain lymphoma is still an open issue. Brain lymphoma usually show elevated 18F-FDG uptake, often higher than other brain tumors or inflammatory processes, but the metabolic behavior of this lymphoma is not still understood. Our aim was to investigate the particular metabolic behavior of this lymphoma. Forty six patients (21 female, 25 male) with histologically-confirmed brain lymphoma who underwent 18F-FDG PET/CT from vertex to the mid-thigh for initial staging were retrospectively evaluated. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, lesion-to-blood pool SUVmax ratio and the tumor to normal brain uptake ratio (T/N ratio) and compared with epidemiological (age, sex, HIV infection) and morphological (tumor size, MRI appearance) characteristics. Thirty-eight patients (83%) had positive 18F-FDG PET/CT (average SUVmax was 15.6 ± 9.2; lesion-to-liver SUVmax ratio 5.8 ± 2.8; lesion-to-blood pool SUVmax ratio 7.1 ± 3.8, T/N ratio 3.1 ± 1.7) at the corresponding brain lesion; the remaining 8 (17%) were not 18F-FDG avid. 18F-FDG avidity was significantly associated with morphological appearance and tumor size and not correlated with other features. 18F-FDG PET/CT detected extracranial disease in two cases (4%) with negative bone marrow biopsies and CT. In conclusion, brain lymphomas are 18F-FDG avid in 83% of cases showing high 18F-FDG uptake and 18F-FDG avidity is correlated with tumor size and morphological appearance of the lesion. PET/CT helped to recognize extracranial disease in two patients.

Diffusional kurtosis imaging for differentiating between high-grade glioma and primary central nervous system lymphoma

BACKGROUND

The aim of this study was to assess the diagnostic accuracy of diffusion kurtosis magnetic resonance imaging parameters for differentiating high-grade gliomas (HGGs) from primary central nervous system lymphomas (PCNSLs).

METHODS

Diffusion parameters, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ// ), radial diffusivity (λ⊥ ); and kurtosis parameters, including mean kurtosis (MK), axial kurtosis (K// ), and radial kurtosis (K⊥ ), were normalized to contralateral normal-appearing white matter (NAWMc) to decrease inter-individual and inter-regional changes across the entire brain, and then compared with the solid parts of 20 HGGs and 11 PCNSLs [median 95% confidence interval (CI), P < 0.004; 0.05/14], significance level, Kolmogorov-Smirnov test, Bonferroni correction].

RESULTS

FA, MD, λ// , and λ⊥ values were higher in HGGs than in PCNSLs, but not significantly [HGGs: 0.209 (95% CI, 0.134-0.338), 1.385 (95% CI, 1.05-1.710), 1.655 (95% CI, 1.30-2.060), 1.228 (95% CI, 0.932-1.480), respectively; PCNSLs: 0.143 (95% CI, 0.110-0.317), 1.070 (95% CI, 0.842-1.470), 1.260 (95% CI, 0.960-1.930), 1.010 (95% CI, 0.782-1.240)], respectively; P = 0.120, 0.010, 0.004, and 0.004, respectively). However, MK and K// were significantly higher in PCNSLs compared with HGGs [PCNSLs: 0.765 (95% CI, 0.697-0.890), 0.787 (95% CI, 0.615-1.030), respectively; HGGs: 0.531 (95% CI, 0.402-0.766), 0.532 (95% CI, 0.432-0.680], respectively; P = 0.001, 0.000, respectively); but not K⊥ [0.774 (95% CI, 0.681-0.899) for PCNSLs; 0.554 (95% CI, 0.389-0.954) for HGGs; P = 0.024].

CONCLUSION

There were significant differences in kurtosis parameters (MK and K// ) between HGGs and PCNSLs, while differences in diffusion parameters between them did not reach significance; hence, better separation was achieved with these parameters than with conventional diffusion imaging parameters. J. Magn. Reson. Imaging 2016;44:30-40.

Unusual relapse of primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare disease which accounts for 1-2 % of non-Hodgkin lymphoma and 3-5 % of primary brain tumor lesions. PCNSL of an immunocompetent patient is an uncommon disease, it is estimated at 4 % of new diagnoses of CNS tumors. The prognosis of PCNSL is poor compared to other extranodal lymphomas, with a 5-year survival estimated between 20 and 40 %. PCNSL relapse occurs either in the original site but still confined to the CNS or exceptionally outside it. Brain magnetic resonance imaging, although not allowing a clear distinction between primary lesions and secondary brain lymphoma is of paramount importance not only for diagnosis but also for monitoring the patient. This manuscript report the case of a patient in whom the PCNSL has relapsed in the cervical spinal cord and also in the liver.

18F-FDG PET in the diagnosis and treatment of primary central nervous system lymphoma

This paper summarizes the usefulness and limitation of positron emission tomography (PET) with (18)F-fluorodeoxyglucose ((18)F-FDG) in the diagnosis and treatment of primary central nervous system lymphoma (PCNSL). The (18)F-FDG uptake in typical PCNSL is about 2.5 times higher than that in the normal gray matter, and the tumor can usually be identified visually. The (18)F-FDG uptake pattern and value provide useful information for differentiating PCNSL from other enhancing malignant brain tumors especially glioblastoma (GB). The (18)F-FDG uptake in typical PCNSL is usually homogenous, and the uptake value is significantly higher than that in GB. However, (18)F-FDG PET often fails to show the presence of tumor in the brain as (18)F-FDG uptake is faint in atypical PCNSL such as disseminated or nonenhancing lesions. (18)F-FDG PET is also useful for evaluating the treatment response at a very early stage after the initial treatment. Pretreatment and posttreatment (18)F-FDG uptake values may have a prognostic value in patients with PCNSL. In conclusion, (18)F-FDG PET is very useful in the diagnosis of typical PCNSL and can differentiate PCNSL from other malignant brain tumors. However, the usefulness of (18)F-FDG PET is limited in the diagnosis of atypical PCNSL.

A systematic approach to the diagnosis of suspected central nervous system lymphoma

Central nervous system (CNS) lymphoma can present a diagnostic challenge. Currently, there is no consensus regarding what presurgical evaluation is warranted or how to proceed when lesions are not surgically accessible. We conducted a review of the literature on CNS lymphoma diagnosis (1966 to October 2011) to determine whether a common diagnostic algorithm can be generated. We extracted data regarding the usefulness of brain and body imaging, serum and cerebrospinal fluid (CSF) studies, ophthalmologic examination, and tissue biopsy in the diagnosis of CNS lymphoma. Contrast enhancement on imaging is highly sensitive at the time of diagnosis: 98.9% in immunocompetent lymphoma and 96.1% in human immunodeficiency virus-related CNS lymphoma. The sensitivity of CSF cytology is low (2%-32%) but increases when combined with flow cytometry. Cerebrospinal fluid lactate dehydrogenase isozyme 5, β2-microglobulin, and immunoglobulin heavy chain rearrangement studies have improved sensitivity over CSF cytology (58%-85%) but have only moderate specificity (85%). New techniques of proteomics and microRNA analysis have more than 95% specificity in the diagnosis of CNS lymphoma. Positive CSF cytology, vitreous biopsy, or brain/leptomeningeal biopsy remain the current standard for diagnosis. A combined stepwise systematic approach outlined here may facilitate an expeditious, comprehensive presurgical evaluation for cases of suspected CNS lymphoma.

Pathology of extra-nodal non Hodgkin lymphomas

In the management of extra-nodal lymphomas it is important to determine whether the tumour has disseminated and whether lymph nodes are involved. Some extra-nodal lymphomas may be the result of random spread of nodal lymphoma. Specific homing, however, determines the site of many extra-nodal lymphomas, as exemplified by cutaneous T-cell lymphomas, which seem to be derived from skin-homing T-cells and mucosa-associated lymphoid tissue lymphomas that show features of the mucosal immune system. Enteropathy-associated T-cell lymphoma is derived from mucosal T-cells in patients with coeliac disease. Immunological sanctuary accounts for the localisation of primary brain, eye and testicular lymphoma. Mantle cell lymphoma frequently causes tumours in the gastrointestinal tract. Random biopsies have shown that a high proportion of patients with this lymphoma have extensive occult involvement of the gastrointestinal tract at the time of first diagnosis. Follicular lymphoma occurs at both nodal and extra-nodal sites, but uncommonly at both sites at the same time. Extra-nodal follicular lymphomas frequently lack t(14;18)(q32;q21) and do not express bcl-2, which are characteristics of the nodal disease. At extra-nodal sites, follicular lymphoma is more likely to be curable than nodal follicular lymphoma. The behaviour of extra-nodal lymphomas cannot be assumed to follow that of their nodal counterparts.

Clinical characteristics and outcome of isolated extracerebral relapses of primary central nervous system lymphoma: a case series

There is very limited data on isolated systemic relapses of primary central nervous system lymphomas (PCNSL). We retrospectively reviewed the clinical characteristics and outcome of 10 patients with isolated systemic disease among 209 patients with PCNSL mainly treated with methotrexate-based chemotherapy (CT) with or without radiation therapy (RT). Isolated systemic relapse remained rare (4.8%, 10/209 patients). Median time from initial diagnosis to relapse was 33 months (range, 3-94). Sites of relapse were mostly extranodal. Three patients presented with early extra-cerebral (EC) relapse 3, 5 and 8 months from the beginning of initial treatment, respectively, and 7 patients had later relapses (range, 17-94 months). Treatment at relapse included surgery alone, RT alone, CT with or without radiotherapy, or CT with autologous stem cell transplantation (ASCT). Median overall survival (OS) after relapse was 15.5 months (range, 5.8-24.5) compared to 4.6 months (range, 3.6-6.5) for patients with central nervous system (CNS) relapse (p = 0.35). In conclusion, isolated systemic relapses exist but are infrequent. Early EC relapse suggests the presence of systemic disease undetectable by conventional evaluation at initial diagnosis. Patient follow-up must be prolonged because systemic relapse can occur as late as 10 years after initial diagnosis. Whether EC relapses of PCNSL have a better prognosis than CNS relapses needs to be assessed in a larger cohort.

Management of immunocompetent patients with primary central nervous system lymphoma

Primary central nervous system (CNS) lymphoma (PCNSL) is a non-Hodgkin lymphoma that arises within and is confined to the CNS. Recent data have suggested an increasing incidence in immunocompetent individuals, with a peak of incidence between 60 and 70 years of age. Patients with PCNSL present mostly with symptoms of increased intracranial pressure. The clinical management of these patients remains controversial, and the optimal treatment for patients with PCNSL has not yet been defined. Surgery, even if macroscopically radical, does not improve survival because of the multifocal and infiltrative nature of PCNSL; furthermore, the deep location of most of these tumors makes patients susceptible to serious and irreversible neurologic sequelae. Corticosteroids have a specific role in the treatment of patients with PCNSL, whose disease is sensitive to them as a chemotherapeutic agent. PCNSL is an extremely radiation-sensitive neoplasm; whole-brain radiation therapy plus corticosteroids was the first modality of treatment for patients with this neoplasm until 10 years ago, with a low cure rate and a high local recurrence rate. PCNSL is also a chemosensitive neoplasm; while the optimal choice, sequence, and combination of appropriate agents for efficacious treatment of patients with PCNSL has yet to be determined. An essential component of therapy must include an adequate drug delivery behind a normal blood-brain barrier. Methotrexate is the agent with the most proven activity in PCNSL. Combined-modality therapy has improved survival, but relapse is still common, and late neurologic toxicity is a significant complication, especially in older patients, who represent the majority of immunocompetent patients with PCNSL.

Comparative clinicopathological study of primary CNS diffuse large B-cell lymphoma and intravascular large B-cell lymphoma

Primary CNS diffuse large B-cell lymphoma (CNS DLBCL) is confined to the CNS, and constitutes a distinct entity. In the present study a series of 40 Japanese patients with CNS DLBCL who presented with neurological, but not systemic symptoms, was reviewed. Median survival was 18.7 months. CD5, CD10, Bcl-6, MUM-1, and Bcl-2 were positive in 30%, 10%, 84%, 100%, and 93% of patients, respectively. All CD10-negative patients had non-germinal center B-cell type. There was no significant difference in survival among the immunophenotypic subgroups. CNS DLBCL appeared to be homogenous as a group, which prompted the comparison with another distinct extranodal entity, intravascular large B-cell lymphoma (IVLBCL) in Japanese patients. CNS DLBCL patients did not differ in age, sex, or immunophenotype, including CD5 positivity, from IVLBCL patients, but were significantly less likely to have poor prognostic parameters than IVLBCL patients: the international prognostic index score was low or low-intermediate in 86% of CNS DLBCL patients and high or high-intermediate in 98% of IVLBCL patients. Notably, despite this difference, their survival curves almost overlapped. The present study highlights the issue of clinical distinctiveness of aggressive extranodal lymphomas, the peculiar migration and localization of which should be further clarified.

Age-incidence patterns of primary CNS tumors in children, adolescents, and adults in England

Around 25% of all tumors in those 0-14 years of age and 9% in those 15-24 years of age involve the CNS. They are the most common cause of cancer-related deaths in both age groups. In adults 25-84 years of age, the proportion of CNS tumors is 2%; 5-year overall survival is 10%-15%; and survivors have considerable morbidity. Comprehensive up-to-date population-based incidence data on these tumors are lacking. We present incidence rates for primary CNS tumors based on data derived from the high-quality national cancer registration system in England. A total of 54,336 CNS tumors of malignant, benign, and uncertain behavior were registered across the whole of England from 1995 through 2003. The age-standardized rates for all ages (0-84 years) was 9.21 per 100,000 person-years. This is higher than previously reported for England because it includes nonmalignant CNS tumors and hence gives a more accurate picture of burden of disease. The age-standardized rates for those 0-14 years of age, 15-24 years of age, and 25-84 years of age were 3.56, 3.26, and 14.57 per 100,000 person-years, respectively. In this article, we describe the changing patterns in the epidemiology of primary CNS tumors in these three age groups with respect to sex, tumor behavior, and histology using the current WHO classification. This information will provide a reference for future studies nationally and internationally and make comparisons relevant and meaningful.

Intensive chemotherapy followed by hematopoietic stem-cell rescue for refractory and recurrent primary CNS and intraocular lymphoma: Société Française de Greffe de Moëlle Osseuse-Thérapie Cellulaire

PURPOSE

The prognosis of relapsing primary CNS lymphoma (PCNSL) is poor. We report the results of a prospective multicenter trial of intensive chemotherapy followed by autologous hematopoietic stem-cell rescue (IC + HCR) in immunocompetent adult patients with PCNSL or intraocular lymphoma (IOL) after failure of high-dose methotrexate-based treatment.

PATIENTS AND METHODS

Salvage treatment consisted of two cycles of high-dose cytarabine and etoposide (CYVE). Intensive chemotherapy combined thiotepa, busulfan, and cyclophosphamide. Forty-three patients (median age, 52 years; range, 23 to 65 years) were included, with relapse (n = 22), refractory disease (n = 17), or a partial response to first-line treatment (n = 4). The response to CYVE was not assessable in three cases because of treatment-related death. Twenty patients (47%) were chemosensitive to CYVE: 15 of them proceeded to IC + HCR. IC + HCR was also administered to 12 patients who did not respond to CYVE. All but one of the 27 patients who underwent IC + HCR entered complete remission.

RESULTS

With a median follow-up of 36 months, the median overall survival was 18.3 months in the overall population, and 58.6 months among patients who completed IC + HCR. The respective median progression-free survival (PFS) times after IC + HCR were 11.6 and 41.1 months. The 2-year overall survival probability was 45% in the whole population and 69% among the 27 patients who received IC + HCR. The 2-year PFS probability was 43% among all the patients and 58% in the IC + HCR subpopulation.

CONCLUSION

IC + HCR is an effective treatment for refractory and recurrent PCNSL.

The utility of body FDG PET in staging primary central nervous system lymphoma

(18)F-Fluorodeoxyglucose (FDG) PET has become an important tool in the management of non-Hodgkin's lymphoma (NHL), but its role in the evaluation of primary CNS lymphoma (PCNSL) has not been established. We investigated the ability of body FDG PET to detect systemic disease in the staging and restaging of PCNSL. The records of 166 PCNSL patients seen at Memorial Sloan-Kettering Cancer Center were examined. Forty-nine patients who underwent body FDG PET for staging of PCNSL were identified. Clinical data were reviewed to determine FDG PET results and their influence on therapy. Body FDG PET disclosed a systemic site of malignancy in 15% of patients. NHL was found in 11% of all patients, 7% of patients at diagnosis, and 27% of patients at CNS relapse. Four percent had a second systemic neoplasm. Workup with conventional staging did not reveal systemic disease, and in 8% of patients, body FDG PET was the only abnormal diagnostic exam suggestive of lymphoma. FDG PET findings altered patient treatment and resulted in additional chemotherapy, surgery, or radiotherapy. Our findings suggest that FDG PET may be more sensitive than conventional body staging and may disclose higher rates of concomitant systemic disease at PCNSL diagnosis. Body FDG PET may be an important noninvasive adjunct to conventional PCNSL staging, and its utility should be evaluated prospectively.

Primary central nervous system lymphoma

Primary central nervous system lymphomas (PCNSL) are aggressive malignancies that arise in distinct anatomical sites, which display unique structural, biological and immunological conditions. So far, despite recent therapeutic advances, these malignancies exhibit one of the worst prognoses among all non-Hodgkin lymphomas (NHL). For a long time, radiotherapy (RT) has been the standard treatment, producing a response rate of 60-65% and a notable neurological improvement in most cases. However, relapse usually occurred within a few months after RT, with a median survival of 14 months and a 5-year survival of approximately 15-24%. Although the introduction of systemic chemotherapy has consistently improved survival, the prognosis of PCNSL is still dismal, with high rates of local relapse and consequent death. Defining the optimum therapeutic management is difficult because of potential selection biases in large retrospective reviews and the limited number of prospective studies. Although studies published on PCNSL are increasing, several therapeutic questions still remain unanswered after a decade of research.

Contribution of F-18 FDG PET-CT in the Detection of Systemic Spread of Primary Central Nervous System Lymphoma

PURPOSE

Primary central nervous system lymphoma (PCNSL) accounts for approximately 3% of all primary brain tumors and 1% of all non-Hodgkin lymphomas. Detection of systemic spread of PCNSL, although rare (4%), is very important since therapy is usually modified. Contrast-enhanced computed tomography (CT) is commonly used for systemic staging of PCNSL. No previous case report is available in the published literature elaborating the potential contribution of F-18 FDG PET in systemic staging of PCNSL. The purpose of this case report was to document the potential usefulness of F-18 FDG-PET in the detection of occult systemic involvement in PCNSL.

MATERIALS AND METHODS

A 50-year-old, immunocompetent, male patient completed successful treatment of PCNSL. As part of a routine pretransplant evaluation he had an F-18 FDG PET coregistered with CT (PET-CT). The PET-CT results were then compared with those of contrast-enhanced CT of the chest, abdomen, and pelvis.

RESULTS

The PET-CT examination detected multiple sites of extranodal systemic disease that were not seen in the contrast-enhanced CT of the chest, abdomen, and pelvis (both studies were performed within 24 hours of each other). Percutaneous ultrasound guided biopsy confirmed the presence of systemic spread of PCNSL. The patient's subsequent therapy was modified to include rituximab with cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP). A follow up PET-CT confirmed resolution of systemic spread.

CONCLUSION

F-18 FDG PET coregistered to CT may be a useful examination in the detection and monitoring for systemic spread of the disease in PCNSL patients.

Primary central nervous system lymphoma: presentation, diagnosis and staging

Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma that affects the brain, spinal cord, leptomeninges, and eyes. The clinical presentation and neuroimaging appearance of PCNSL differ in immunocompetent patients and in those with acquired immunodeficiency syndrome (AIDS). A magnetic resonance (MR) image of the brain in immunocompetent patients with PCNSL typically demonstrates one or more homogeneously enhancing lesions located in the periventricular white matter, characteristically spanning the corpus callosum. In patients with AIDS, multiple ring-enhancing lesions are more common. After neuroimages raising the suspicion of PCNSL are obtained, a definitive diagnosis should be established in both immunocompetent and AIDS patients by performing pathological analysis of cerebrospinal fluid (CSF), vitreous fluid, or a biopsy specimen. Brain biopsy sampling remains the gold standard for PCNSL diagnosis in all patients, although the possibility of establishing routine, minimally invasive diagnostic procedures in which Epstein-Barr virus polymerase chain reaction (PCR) analysis of the CSF and nuclear imaging are used is currently under investigation in the population of patients with AIDS. At the time of diagnosis, the patient should undergo further evaluation, which should include a physical examination, ophthalmic evaluation with a slit-lamp examination, serum lactate dehydrogenase levels, human immunodeficiency virus testing, computed tomography scans of the chest/abdomen/pelvis, bone marrow biopsy sampling, contrast-enhanced brain MR imaging, and lumbar puncture (LP). Testicular ultrasonography studies should be considered in men. In patients who cannot undergo LP or in those with evidence of spinal cord dysfunction, contrast-enhanced MR imaging of the entire spine should be considered.

Detection of subclinical systemic disease in primary CNS lymphoma by polymerase chain reaction of the rearranged immunoglobulin heavy-chain genes

PURPOSE

To search for subclinical systemic disease in bone marrow and peripheral blood in patients with primary CNS lymphoma (PCNSL) to elucidate whether extracerebral relapse may represent a sequel of initial occult systemic disease rather than true extracerebral spread.

PATIENTS AND METHODS

Bone marrow and peripheral-blood specimens of 24 PCNSL patients were examined using polymerase chain reaction (PCR) for analysis of clonally rearranged immunoglobulin heavy-chain (IgH) genes.

RESULTS

Identical dominant PCR products were found in bone marrow aspirates, blood samples, and tumor biopsy specimens of two patients, indicating that the same tumor cell population is present in the CNS and in extracerebral sites. Follow-up IgH PCR performed in one of these patients in complete remission 24 months after diagnosis yielded a persistent monoclonal product in the blood. An oligoclonal IgH rearrangement pattern was found in the tumor specimen of two other patients, whereas bone marrow and blood samples demonstrated the same dominant PCR products. Follow-up PCR showed a persistent monoclonal amplificate in blood in one of these patients 27 months after diagnosis.

CONCLUSION

It could be demonstrated for the first time that subclinical systemic disease can be present in PCNSL patients at initial diagnosis. Our findings may have an impact on the understanding of PCNSL pathogenesis and the extent of staging and treatment.

Relapse of primary central nervous system lymphoma: clinical features, outcome and prognostic factors

Data on relapsed primary central nervous system lymphoma (PCNSL) are limited. We have evaluated the clinical characteristics and outcome of relapsed PCNSL patients from two German trials. Patients with relapsed disease after primary treatment were studied. Primary therapy consisted of high-dose methotrexate-based chemotherapy in all patients. Treatment for relapse was not predetermined. After a median follow-up of 22.5 months, 52 (36%) patients with relapse were identified among 143 patients with complete remission (CR) after primary treatment. The median disease-free survival was 10.25 (3-47.5) months. The median age at relapse was 59 years. Forty-four of 51 evaluable patients relapsed within the CNS, 6 systemically and one both cerebrally and systemically. The median survival time after first relapse was 4.5 (0.5-40.5) months. Karnofsky performance status (KPS) at relapse (P = 0.004), site of relapse (isolated systemic versus other, P = 0.049) and treatment for relapse (versus no treatment, P = 0.001) were independent prognostic factors for survival after relapse in multivariate analysis. Survival of patients with relapsed PCNSL is poor despite high response rates to salvage therapy. Good KPS, isolated systemic relapse and treatment for relapse were significantly associated with longer survival.

Primary CNS lymphoma

Primary CNS lymphoma (PCNSL), an uncommon form of extranodal non-Hodgkin's lymphoma (NHL), has increased in incidence during the last three decades and occurs in both immunocompromised and immunocompetent hosts. PCNSL in immunocompetent patients is associated with unique diagnostic, prognostic, and therapeutic issues, and the management of this malignancy is different from that of other forms of extranodal NHL. Characteristic imaging features should be suggestive of the diagnosis, avoidance of corticosteroids, if possible, and early neurosurgical consultation for stereotactic biopsy. Because PCNSL may involve the brain, CSF, and eyes, diagnostic evaluation should include assessment of all of these regions as well as screening for possible occult systemic disease. Resection provides no therapeutic benefit and should be reserved for the rare patient with neurologic deterioration due to brain herniation. Whole-brain radiation therapy (WBRT) alone is insufficient for durable tumor control and is associated with a high risk of neurotoxicity in patients older than age 60. Neurotoxicity typically is associated with significant cognitive, motor, and autonomic dysfunction, and has a negative impact on quality of life. Chemotherapy and WBRT together improve tumor response rates and survival compared with WBRT alone. Methotrexate-based multiagent chemotherapy without WBRT is associated with similar tumor response rates and survival compared with regimens that include WBRT, although controlled trials have not been performed. The risk of neurotoxicity is lower in patients treated with chemotherapy alone.

Clinical Features and Diagnosis of Primary Central Nervous System Lymphoma

This article reviews the clinical features of primary central nervous system lymphoma (PCNSL) in immunocompetent and immunocompromised patients. Clinical presentation, differential diagnosis, diagnostic testing, and staging evaluation in both immunocompetent and AIDS patients who have PCNSL are discussed. The differing role of biopsy in these two populations also is addressed.

New Treatment Approaches in Primary Central Nervous System Lymphoma

A major advance in the treatment of primary central nervous system lymphoma (PCNSL) was made when the addition of chemotherapy to radiotherapy was shown to improve patient survival significantly. However, few chemotherapeutic agents are able to cross the blood-brain barrier. New therapeutic approaches in PCNSL are based on: the treatment of systemic non-Hodgkin's lymphomas with monoclonal antibodies and intensive chemotherapy followed by hematopoietic stem cell rescue, new chemotherapeutic agents with central nervous system penetration, or blood-brain barrier disruption to enhance drug delivery to the brain. This article discusses the rationale and results of these innovative approaches.

Report of an international workshop to standardize baseline evaluation and response criteria for primary CNS lymphoma

Standardized guidelines for the baseline evaluation and response assessment of primary CNS lymphoma (PCNSL) are critical to ensure comparability among clinical trials for newly diagnosed patients. The relative rarity of this tumor precludes rapid completion of large-scale phase III trials and, therefore, our reliance on the results of well-designed phase II trials is critical. To formulate this recommendation, an international group of experts representing hematologic oncology, medical oncology, neuro-oncology, neurology, radiation oncology, neurosurgery, and ophthalmology met to review current standards of reporting and to formulate a consensus opinion regarding minimum baseline evaluation and common standards for assessing response to therapy. The response guidelines were based on the results of neuroimaging, corticosteroid use, ophthalmologic examination, and CSF cytology. A critical issue that requires additional study is the optimal method to assess the neurocognitive impact of therapy and address the quality of life of PCNSL survivors. We hope that these guidelines will improve communication among investigators and comparability among clinical trials in a way that will allow us to develop better therapies for patients.

Diagnosis and treatment of primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is an uncommon form of non-Hodgkin's lymphoma (NHL) that has been increasing in incidence over the past three decades. Unlike systemic extranodal NHL, the response to therapy for PCNSL patients has been somewhat unsatisfactory. However, methotrexate-based chemotherapy and whole-brain radiotherapy have improved the outcome of patients. Unfortunately, treatment-related neurotoxicity is common, especially in the elderly. Although progress has been made in treating PCNSL, there remains no optimal methotrexate dose or frequency. Treatment of recurrence also remains controversial. These important questions have prompted several clinical studies looking at novel ways to intensify chemotherapy and limit neurotoxicity.

Multicentric involvement of non-Hodgkin's lymphoma in the central nervous system and testis--case report

A 73-year-old male presented with diffuse mixed B cell lymphoma with involvement of the central nervous system (CNS) and testis manifesting as mild disorientation and aphasia. A left frontal cerebral mass and a right testicular tumor were found, and both lesions were surgically resected. Histological examination revealed diffuse mixed B cell type malignant lymphoma in the CNS and testis. The patient received irradiation to the head, and his initial symptoms improved. Pelvic computed tomography revealed enlargement of the contralateral testis and prostate. Needle biopsy confirmed lymphoma. The patient died 5 months after the initial diagnosis of septic shock. Autopsy examination revealed lymphoma cell invasion of the lung, bone marrow, prostate gland, and thalamus, but without involvement of the systemic lymph nodes. In a patient with an intracranial lymphoma, it is important to determine if the lesion is primary or metastatic and to plan medical treatment including systemic chemotherapy as soon as possible. Improvement of the prognosis of systemic non-Hodgkin's lymphoma with CNS involvement requires the detection and effective treatment of systemic lesions as well as the control of the CNS lesions.

Incidence, clinical features, treatment and outcome of primary central nervous system lymphoma in Norway

The incidence of primary central nervous system lymphoma (PCNSL) has been reported to increase in some parts of the world, while being stable in other regions. In an attempt to characterize the incidence rate, clinical features, treatment, outcome, and prognostic factors of PCNSL in Norway, we report our experience in a large unselected series of patients. Clinical features, histological diagnosis, radiological findings, treatment, and outcome of all patients diagnosed with PCNSL in Norway in the years 1989-1998 were registered. During the 10-year period 58 new cases of histologically verified PCNSL were registered in Norway. The annual incidence rate of PCNSL was on average 1.34 cases per million people with a non-significant increasing trend (p=0.069). For patients diagnosed before death (n=45) the estimated survival following histological diagnosis was 55%, 47%, and 23% at 1, 2, and 5 years, respectively. In Cox-regression analysis age, WHO performance status and treatment had independent prognostic impact on survival. In the studied decade, there was a non-significant trend towards increased incidence of PCNSL, perhaps due to increased availability of diagnostic imaging, especially magnetic resonance imaging.