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.

https://jamanetwork.com/journals/jamaneurology/articlepdf/1556618/nnr120005_311_319.pdf

A Systematic Approach to the Diagnosis of Suspected Central Nervous System Lymphoma

Imaging of primary central nervous system lymphoma

Clinical Haematology, Nottingham University Hospitals NHS Trust, Nottingham, Department of Haematology, University College Hospital, London, Department of Haematology, Division of Cancer Sciences, School of Medical Sciences, Aintree Hospital NHS Trust, Liverpool, University of Manchester, Manchester, Velindre Cancer Centre, Cardiff, Department of Haematology, Barking, Havering and Redbridge University Hospitals, Essex, Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, Nottingham, Department of Neuropsychology, Barking, Havering and Redbridge University Hospitals, Essex, Department of Medical Oncology, Southampton General Hospital, Southampton, and Department of Haematology, Beatson West of Scotland Cancer Centre, Glasgow, UK

https://onlinelibrary.wiley.com/doi/pdf/10.1111/bjh.15661

Guidelines for the diagnosis and management of primary central nervous system diffuse large B-cell lymphoma

Conventional magnetic resonance (MR) imaging of space-occupying lesions may answer most of the questions concerning the diagnosis and subsequent treatment strategies if patient age, clinical and paraclinical findings are considered as well. However, crucial and relevant differential diagnoses require additional MR methods, such as diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI) and magnetic resonance spectroscopy (MRS). In necrotic ring-enhancing lesions DWI may detect inflammatory processes, whereas characteristics of the peritumoral area may help to distinguish between metastases and glioblastomas. In solid tumors DWI, PWI and MRS may also aid the differentiation between low-grade gliomas and malignant tumors, such as gliomas WHO (World Health Organization) grade III and IV and lymphomas. This review briefly explains special MR methods with respect to brain tumors and illustrates the diagnostic pathways necessary for supplying a reliable diagnosis as well as optimal pre-operative imaging of space-occupying brain lesions.

Neuroradiological viewpoint on the diagnostics of space-occupying brain lesions.

OBJECTIVE. Tumefactive demyelinating lesions (TDLs) remain one of the most common brain lesions to mimic a brain tumor, particularly primary CNS lymphoma (PCNSL) and high-grade gliomas. The purpose of our study was to evaluate the ability of apparent diffusion coefficient (ADC) values and conventional MRI features to differentiate TDLs from PCNSLs and high-grade gliomas. MATERIALS AND METHODS. Seventy-five patients (24 patients with TDLs, 28 with PCNSLs, and 23 with high-grade gliomas) with 168 brain lesions (70 TDLs, 68 PCNSLs, and 30 high-grade gliomas) who underwent DWI before surgery or therapy were included in the study. Minimum ADC (ADCmin) and average ADC (ADCavg) values were calculated for each lesion. ANOVA and ROC analyses were performed. ROC analyses were also performed for the presence of incomplete rim enhancement and for the number of lesions. Multiple-variable logistic regression with ROC analysis was then performed to evaluate performance in multiple-variable models. RESULTS. ADCmin was st...

/pdf/performance-of-apparent-diffusion-coefficient-values-and-32obne1jx3.pdf

Performance of Apparent Diffusion Coefficient Values and Conventional MRI Features in Differentiating Tumefactive Demyelinating Lesions From Primary Brain Neoplasms.

Objective: To record the MR imaging features of primary central nervous system lymphoma (PCNSL) and compare these features in monofocal and multifocal disease. Materials and Methods: Twenty-one cases of monofocal disease were compared to five cases of multifocal disease. All patients were examined by nonenhanced and contrast-enhanced MRI. Tumor location, tumor size, signal intensity, enhancement characteristics, age distribution, peritumoral edema, cystic changes, and the presence of calcifications were assessed. The MRI features were compared between the monofocal and multifocal disease cases. Results: The 26 cases, including both the monofocal and multifocal cases, exhibited 37 lesions. Contrast-enhanced images showed variable enhancement patterns: homogeneous enhancement (33 lesions), ring-like enhancement (2), and ‘open-ring-like’ enhancement (2). The ‘notch sign’ was noted in four of 33 homogeneously enhancing lesions. One case of hemorrhage and three cases of cystic formation were observed. Intra-tumoral calcification was not found. The frontal lobe, the corpus callosum and the basal ganglia were commonly affected in both the monofocal and multifocal groups. Tumor size differed significantly between the two groups (t = 3.129, p 0.05) and the signal characteristics (p > 0.05) between the two groups. Conclusion: Our data show that PCNSL has a variable enhancement pattern on MR images. We first reported two lesions with an ‘open-ring’ enhancement as well as four cases with a ‘notch sign’. Monofocal PCNSL cases typically have larger sized tumors with mild or moderate enhancement.

/pdf/mri-findings-of-primary-cns-lymphoma-in-26-immunocompetent-zqqn6m2f0u.pdf

Elisabeth M. Ravarani

Papers

MRI findings of primary CNS lymphoma in 26 immunocompetent patients