Intracranial Marginal Zone B-Cell Lymphoma Mimicking Meningioma

Rare central nervous system lymphomas

Central nervous system (CNS) lymphomas are rare malignancies characterised by lymphoid infiltration into the brain, spinal cord, cranial nerves, meninges and/or eyes in the presence or absence of previous or concurrent systemic disease. Most CNS lymphomas are of the diffuse large B-cell lymphoma (DLBCL) subtype for which treatment strategies, particularly the use of high-dose methotrexate-based protocols and consolidation with autologous stem cell transplantation, are well established. Other histopathological subtypes of CNS lymphoma are comparatively less common with published data on these rare lymphomas dominated by smaller case series and retrospective reports. Consequently, there exists little clinical consensus on the optimal methods to diagnose and manage these clinically and biologically heterogeneous CNS lymphomas. In this review article, we focus on rarer CNS lymphomas, summarising the available clinical data on incidence, context, diagnostic features, reported management strategies, and clinical outcomes.

Leptomeningeal metastasis in a marginal zone lymphoma, presenting as a delirium: case report

Background

Hematologic malignancies can spread to the central nervous system (CNS), either as focal lesions or as leptomeningeal disease. Marginal zone lymphoma (MZL) is a low-grade non-Hodgkin lymphoma and generally presents as an indolent disease. This case report illustrates an unexpected diagnosis of leptomeningeal metastasis in an MZL, presenting as a delirium without B symptoms, pronounced hematologic progression or abnormalities on cerebral imaging.

Case presentation

An 80-year-old patient with a medical history of monoclonal B-cell lymphocytosis (MBL) with a clone indicative for an MZL, presented to the emergency and the geriatric departments with a recent cognitive deterioration and behavioral changes. MMSE score was 18/30. After excluding the most common etiologies through classical work-up including a normal head magnetic resonance imaging, a lumbar puncture was performed. In the cerebrospinal fluid an elevated protein level and increased lymphocyte count were identified, whereas beta-amyloid and tau protein levels were normal. Immunophenotyping of the lymphocytes confirmed CNS invasion by the MZL clone. Staging revealed mild splenomegaly. Prednisolone, intrathecal and systemic chemotherapy were initiated, leading to quick cognitive improvement with a final MMSE score of 28/30.

Conclusions

To the best of our knowledge a delirium in an older patient due to leptomeningeal disease in MZL has never been described. To date, rare reports of CNS invasion by MZL describe focal intracranial lesions. After exclusion of common etiologies, physicians should remain vigilant when confronted with a patient with history of MBL presenting neurological symptoms. This case illustrates the importance of low threshold for lumbar punctures in this population, also for those patients with normal imaging studies.

Extranodal Marginal Zone Lymphoma of the Central Nervous System

Extranodal marginal zone lymphoma of the central nervous system (CNS EMZBL) is a rare disease. We present a review of the literature and describe its presentation, differential diagnosis, treatment options, and outcomes. Systematic search of PubMed, Medline, and Embase databases via the Ovid engine for primary articles and case reports yielded 37 unduplicated peer-reviewed articles of CNS EMZBL. We identified 69 cases in these articles and 1 unreported case at our institution, which were included for this review's analysis. Median age at diagnosis was 55 years (range, 18-78 years), with a female preponderance of 77% (n = 54). Most common presenting symptoms were headache in 43% (n = 30), seizures in 31% (n = 22), and visual defects in 27% (n = 19). The most common treatment modalities were localized therapies, which were provided to 67% (n = 47) of cases. These included radiotherapy in 27% (n = 19), radiotherapy with surgery in 24% (n = 17), and surgery alone in 16% (n = 11). Ninety percent (n = 63) of patients had a median follow-up of 23 months. Complete remission was experienced by 77% (n = 49) patients, and 22% (n = 14) were alive with disease. Three patients had evidence of relapse, and one patient died. CNS EMZBL is an indolent, low-grade, radiosensitive lymphoma with good treatment outcomes and prognosis. It is an important differential to consider in extra-axial dural-based masses. Individualized management plans, with preference given to localized treatment options, should be considered after factoring in the site and extent of disease, its resectability, and the expected adverse effects of systemic therapy.