Primary central nervous system lymphoma

Comparative evaluation of 11C-methionine and 18F-fluorodeoxyglucose positron emission tomography for distinguishing between primary central nervous system lymphoma and isocitrate dehydrogenase-wildtype glioblastoma

PURPOSE

Distinguishing between primary central nervous system lymphoma (PCNSL) and isocitrate dehydrogenase (IDH)-wildtype glioblastoma is important for therapeutic decision-making. This study aimed to compare the performance of 11C-methionine (MET) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for distinguishing between these two major malignant brain tumors.

METHODS

We retrospectively conducted qualitative and semiquantitative analyses of pre-treatment MET and FDG PET/computed tomography (CT) images of 22 patients with PCNSL and 64 patients with IDH-wildtype glioblastoma. For semiquantitative analysis, we calculated the tumor-to-normal tissue (T/N) ratio by dividing the maximum standardized uptake value (SUV) for the tumor (T) by the average SUV for the normal tissue (N). For performance evaluation, we employed receiver operating characteristic curve analysis and calculated the areas under the curve (AUC) values.

RESULTS

In the qualitative analysis, all PCNSLs and IDH-wildtype glioblastomas were MET-positive, while 95% and 84% of PCNSLs and IDH-wildtype glioblastomas, respectively, were FDG-positive. Eleven patients were excluded from the FDG PET/CT semiquantitative analysis because of hyperglycemia. There was no difference in MET T/N ratio between PCNSL and IDH-wildtype glioblastoma (p = 0.37). FDG T/N ratio was significantly higher in PCNSL than in IDH-wildtype glioblastoma (p < 0.001). The AUC value for distinguishing PCNSL from IDH-wildtype glioblastoma was significantly higher for the FDG T/N ratio (0.871) than for the MET T/N ratio (0.565) (p = 0.0027).

CONCLUSION

MET PET could detect both PCNSL and IDH-wildtype glioblastoma, but unlike FDG PET, it could not distinguish between these two major malignant brain tumors.

Differentiating between Primary Central Nervous System Lymphoma and Glioblastoma: The Diagnostic Value of Combining 18F-fluorodeoxyglucose Positron Emission Tomography with Arterial Spin Labeling

Using conventional magnetic resonance imaging (MRI) methods, the differentiation of primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is often difficult due to overlapping imaging characteristics. This study aimed to evaluate the diagnostic value of combining ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) with arterial spin labeling (ASL) for differentiating PCNSL from GBM. In all, 20 patients with PCNSL and 55 with GBM were retrospectively examined. From the FDG-PET data, the maximum standardized uptake values (SUVmax) and the ratio of tumor to normal contralateral gray matter (T/N_SUVmax) were calculated. From the ASL data, the T/N ratio of the maximum tumor blood flow (relative TBFmax: rTBFmax) was obtained. Diagnostic performance of each parameter was analyzed using univariate and multivariate logistic regression analyses and receiver-operating characteristic (ROC) curve analyses. A generalized linear model was applied for comparing the performance of FDG-PET and ASL individually, and in combination. In univariate analysis, SUVmax and T/N_SUVmax were statistically higher in patients with PCNSL and rTBFmax was higher in patients with GBM. In the multivariate analysis, T/N_SUVmax and rTBFmax were statistically independent. The sensitivity, specificity, and area under the curve (AUC) for discriminating PCNSL from GBM were 100%, 87.3%, and 0.950 in T/N_SUVmax; 90%, 72.7%, and 0.824 in rTBFmax; and 95%, 96.4%, and 0.991 in the combined model, respectively. The combined use of T/N_SUVmax and rTBFmax may contribute to better differentiation between PCNSL and GBM.

Genetic evidence implies that primary and relapsed tumors arise from common precursor cells in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare subtype of lymphoma that arises within the brain or the eyes. PCNSL recurs within the central nervous system (CNS) in most relapsed cases, whereas extra‐CNS relapse is experienced in rare cases. The present study aimed at identifying the presence of common precursor cells (CPC) for primary intra‐ and relapsed extra‐CNS tumors, and further assessing the initiating events in bone marrow (BM). Targeted deep sequencing was carried out for five paired primary intra‐ and relapsed extra‐CNS tumors of PCNSL. Two to five mutations were shared by each pair of intra‐ and extra‐CNS tumors. In particular, MYD88 mutations, L265P in three and P258L in one, were shared by four pairs. Unique somatic mutations were observed in all five intra‐CNS tumors and in four out of five extra‐CNS tumors. Remarkably, IgH clones in the intra‐ and the extra‐CNS tumors in two pairs were distinct from each other, whereas one pair of tumors shared identical monoclonal IgH rearrangement. In a cohort of 23 PCNSL patients, L265P MYD88 mutations were examined in tumor‐free BM mononuclear cells (MNC) in which the PCNSL tumors had L265P MYD88 mutations. L265P MYD88 mutations were detected by a droplet digital PCR method in nine out of 23 bone marrow mononuclear cells. These results suggest that intra‐ and extra‐tumors are derived from CPC with MYD88 mutations in most PCNSL, arising either before or after IgH rearrangement. The initiating MYD88 mutations may occur during B‐cell differentiation in BM.

Primary adrenal lymphoma with secondary central nervous system involvement: a case report and review of the literature

Approximately 10%-20% of all systemic lymphomas have central nervous system (CNS) involvement, which has been correlated to a worsened prognosis. It is well known that secondary involvement of the adrenal glands may occur in up to 25% of patients during the course of diffuse lymphoma. Primary adrenal lymphoma (PAL), however, is a different entity, and it is defined as the presence of adrenal lymphoma without evidence of either nodal involvement or leukemia. It has been shown that this occurrence is rarely accompanied by extranodal involvement, such as in the CNS. PAL exhibits a tendency for CNS relapse and this possibility should be examined even before symptoms are present. Herein we present a patient with PAL and secondary CNS involvement.

Diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy in adults accounting for 31% of all NHL in Western Countries. Following, morphological, biological and clinical studies have allowed the subdivision of DLBCLs into morphological variants, molecular and immunophenotypic subgroups and distinct disease entities. However, a large number of cases still remain biologically and clinically heterogeneous, for which there are no clear and accepted criteria for subclassification; these are collectively termed DLBCL, not otherwise specified (NOS). DLBCL-NOS occurs in adult patients, with a median age in the seventh decade, but the age range is broad, and it may also occur in children. Clinical presentation, behaviour and prognosis are variable, depending mainly of the extranodal site when they arise. These malignancies present in localized manner in approximately 20% of patients. Disseminated extranodal disease is less frequent, and one third of patients have systemic symptoms. Overall, DLBCLs are aggressive but potentially curable malignancies. Cure rate is particularly high in patients with limited disease with a 5-year PFS ranging from 80% to 85%; patients with advanced disease have a 5-year PFS ≈ 50%. The International Prognostic Index (IPI) and age adjusted IPI (aaIPI) are the benchmarks of DLBCL prognosis. First-line treatment for patients with DLBCL is based on the individual IPI score and age, and three major subgroups should be considered: elderly patients (>60 years, aaIPI=0-3); young patients with low risk (<60 years, aaIPI=0-1); young patients with high risk (<60 years, aaIPI=2-3). The combination of the anti-CD20 monoclonal antibody rituximab and CHOP chemotherapy, every 14 or 21 days, is the standard treatment for DLBCL patients. Recent randomized trials suggest that high-dose chemotherapy supported by autologous stem cell transplant (HDC/ASCT) should not be used as upfront treatment for young high-risk patients outside prospective clinical trials. HDC/ASCT is actually recommended in young patients who did not achieve CR after first-line chemotherapy. Consolidation radiotherapy should be reserved to patients with bulky disease who did not achieve CR after immunochemotherapy. Patients with high IPI score, which indicates increased LDH serum level and the involvement of more than one extranodal site, and patients with involvement of certain extranodal sites (a.e., testes and orbit) should receive CNS prophylaxis as part of first-line treatment. HDC/ASCT should be considered the standard therapy for DLBCL patients with chemotherapy-sensitive relapse. Overall results in patients who cannot be managed with HDC/ASCT due to age or comorbidity are disappointing. New effective and less toxic chemotherapy drugs or biological agents are also worth considering for this specific and broad group of patients. Several novel agents are undergoing evaluation in DLBCL; among other, immunomodulating agents (lenalidomide), m-TOR inhibitors (temsirolimus and everolimus), proteasome inhibitors (bortezomib), histone deacetylase inhibitors (vorinostat), and anti-angiogenetic agents (bevacizumab) are being investigated in prospective trials.

Primary lymphoma of the cranial vault: case report and a systematic review of the literature

BACKGROUND

Bone involvement is a common finding in many types of lymphoma. Cranial vault involvement is extremely rare, and the majority of patients are found at staging to have concurrent disease in lymph nodes. Thirty-eight cases of primary lymphoma of the cranial vault have been reported to date.

METHODS

This article presents a rare case of primary cranial vault lymphoma and conducts a systematic review of the current literature. A total of 36 articles comprising 38 cases were included for analysis. The relevant demographic, clinical, and imaging characteristics, as well as the treatment and outcomes of this unique disease presentation were studied.

RESULTS

The average patient age was 60 years. There was no significant difference in patient gender. The predominant patient complaint was a subcutaneous scalp mass. Of the patients, 11.7% were immunocompromised. CT scans showed signs of osteolysis in 74% of lesions and hyperostosis in 5%, and the cranial vault was observed as normal in 18% of cases. MRI was performed in 23 cases. There was a wide range of histological subtypes, with a slight predominance of diffuse large B-cell lymphoma. Treatment consisted of surgery alone, surgery followed by radiotherapy, and surgery followed by radiotherapy and chemotherapy. The follow-up periods ranged from 5 months to 6 years, with a median value of 7 months. Sixteen patients were followed up to 12 months; 13 of them were alive at 1 year from diagnosis.

CONCLUSION

Primary cranial vault lymphoma is an extremely rare finding. It should be considered in the differential diagnosis of scalp masses. Although the analysis of outcome of the reported cases is difficult because of the small number of occurrences of this entity and the variability of follow-up, a combination of surgery, radiotherapy, and chemotherapy seems to offer better outcomes.

Primary central nervous system lymphomas: a validation study of array-based comparative genomic hybridization in formalin-fixed paraffin-embedded tumor specimens

PURPOSE

Only a limited number of genetic studies have been conducted in primary central nervous system lymphomas (PCNSL), partly due to the rarity of the tumors and the very limited amount of available tissue. In this report, we present the first molecular characterization of copy number abnormalities (CNA) of newly diagnosed PCNSL by array-based comparative genomic hybridization (aCGH) in formalin-fixed paraffin-embedded (FFPE) specimens and compare the results with matched, frozen tumor specimens.

EXPERIMENTAL DESIGN

We conducted aCGH in FFPE tissues from PCNSL. Results were compared with matched, paired, frozen tumors.

RESULTS

Our analysis confirmed the good to fair quality and reliability of the data generated from limited amounts of tumoral FFPE tissue. Overall, all PCNSL cases were characterized by highly complex karyotypes, with a median of 23 CNAs per patient (range, 17-47). Overall, 20 chromosomal regions were recurrently found in more than 40% of cases. Deletions of 6p21, 6q, and 9p21.3 and gain of 12q12-q24.33 were the commonest CNAs. Other minimal affected regions were defined, and novel recurrent CNAs affecting single genes were identified in 3q26.32 (TBL1XR1) and 8q12.1 (TOX).

CONCLUSIONS

The results obtained are encouraging. Larger archival tissue collections can now be analyzed to complement the still fragmented knowledge we have of the genetic basis of the PCNSL.

Monoclonal antibodies in neuro-oncology: Getting past the blood-brain barrier

Monoclonal antibodies (mAbs) are used with increasing success against many tumors but, for brain tumors, the blood-brain barrier (BBB) is a special concern. The BBB prevents antibody entry to the normal brain; however, its role in brain tumor therapy is more complex. The BBB is closest to normal at micro-tumor sites; its properties and importance change as the tumor grows. In this review, evolving insight into the role of the BBB is balanced against other factors that affect efficacy or interpretation when mAbs are used against brain tumor targets. As specific examples, glioblastoma multiforme (GBM), primary central nervous system lymphoma (PCNSL) and blood-borne metastases from breast cancer are discussed in the context of treatment, respectively, with the mAbs bevacizumab, rituximab, and trastuzumab, each of which is already widely used against tumor outside the brain. It is suggested that success against brain tumors will require getting past the BBB in two senses: physically, to better attack brain tumor targets and conceptually, to give equal attention to problems that are shared with other tumor sites.

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.

[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.

Favorable outcome of primary CNS anaplastic large cell lymphoma in an immunocompetent patient

A 9-year-old immunocompetent male patient with primary central nervous system anaplastic large cell lymphoma was treated with 5 cycles of intensive chemotherapy including high-dose Ara-C, high-dose methotrexate, etoposide, and carmustine along with intraventricular chemotherapy followed by high-dose thiotepa and carboplatin with autologous peripheral blood hematopoietic stem cell transplantation. He received radiotherapy as the final therapy and has remained in remission for 26 months off therapy.

CT and MR imaging features of primary central nervous system lymphoma in Norway, 1989-2003

BACKGROUND AND PURPOSE

Studying imaging findings of non-acquired immunodeficiency syndrome (AIDS) primary central nervous system lymphoma (PCNSL), we hypothesized that the imaging presentation has changed with the increasing incidence of PCNSL and is related to clinical factors (eg, time to diagnosis and the patient's being diagnosed alive or at postmortem examination).

MATERIALS AND METHODS

Chart and histologic reviews of patients recorded as having PCNSL during 1989-2003 in the Norwegian Cancer Registry identified 98 patients with non-AIDS PCNSL; 75 had available imaging. CT and MR images from the first diagnostic work-up after onset of symptoms but before histologic diagnosis were reviewed.

RESULTS

CT and/or MR imaging in the 75 patients revealed no lesion in 10 (13%), a single focal lesion in 34 (45%), multiple focal lesions in 26 (35%), and disseminated lesions in 5 (7%) patients. All together, we identified 103 focal lesions (single/multiple): 63% in white matter, 56% abutting the ventricular surface, and 43% in the frontal lobes); 100% (102/102 lesions evaluated with contrast) showed contrast enhancement. The median time from imaging to diagnosis for patients with no, single, multiple, or disseminated lesions was 32, 3, 5, and 3 weeks, respectively (P = .01). Patients with no or disseminated lesions were more often diagnosed at postmortem examination (P = .06). Imaging findings were practically unchanged during the consecutive 5-year periods.

CONCLUSIONS

White matter periventricular contrast-enhancing single or multiple focal lesions were typical of non-AIDS PCNSL. No or disseminated lesions heightened the risk of delayed or postmortem diagnosis. Although the incidence of non-AIDS PCNSL has increased, its presentation at imaging remains unchanged.

Primary lymphoma of the central nervous system: epidemiology, pathology and current approaches to diagnosis, prognosis and treatment

An overview of the current approaches to the management of patients with primary central nervous system lymphoma (PCNSL) is provided. Although accumulating evidence demonstrates that PCNSL is a curable type of brain tumor, in many cases establishing the diagnosis and overcoming chemotherapeutic resistance remain significant obstacles. The issue of treatment-related neurotoxicity is also a central consideration in treatment planning. The introduction of highly active antiretroviral therapy has had a major impact on this disease in that the incidence of AIDS-related central nervous system lymphoma, once highly prevalent in the 1980s and 1990s, has now virtually disappeared. However, the problem of diagnostic delays secondary to steroid effects, radiation-induced neurotoxicity and methotrexate resistance represent unique and important problems in this disease. The use of anti-CD20 antibody in this disease represents the first application of biologically based targeted therapies for PCNSL; however, the overall impact of this modality in brain lymphoma awaits further evaluation in ongoing studies The application of proteomic as well as gene expression technologies is yielding insights into PCNSL pathogenesis, in particular specific oncogenic pathways, which may be exploited to develop new therapies.

The rationale and role of radiation therapy in the treatment of patients with diffuse large B-cell lymphoma in the Rituximab era

Developments in the evaluation and systemic management of diffuse large B-cell lymphoma (DLBCL) require ongoing assessment of the role of external beam radiotherapy in management. This review assesses data regarding the use of radiotherapy in the initial management of early stage and advanced DLBCL, and considers the implications of bulky and residual disease, and the contribution of PET scanning, to decisions regarding the use of radiotherapy after chemotherapy. Limited R-CHOP plus radiotherapy, or full dose R-CHOP alone, are both likely to cure approximately 90% of patients with low risk early stage disease. The choice of therapy will depend on considerations of acute and late toxicity of the two approaches, taking into account individual patient risk profiles and preferences. Unfavorable early-stage and advanced-stage disease require treatment with full dose R-CHOP. The presence of bulky disease predicts for a higher risk of relapse, which may be partly ameliorated by the addition of radiotherapy. The rapidity of response on PET scanning, the presence of a posttherapy residual mass, the potential toxicity of radiotherapy and the available salvage options all need to be considered on a patient by patient basis, when considering the use of radiotherapy for advanced disease.