Primary central nervous system lymphoma: advances in MRI and PET imaging

Abstract

Contrast enhanced magnetic resonance imaging (CE-MRI) remains the imaging modality of choice for initial workup, staging, and response assessment after therapy in patients with primary central nervous system lymphoma (PCNSL). While CE-MRI is a sensitive test to detect blood brain barrier (BBB) dysfunction, it does not biologically represent the true tumor burden. Current response assessment criteria relies heavily on two dimensional anatomical measurements on post contrast T1-weighted (T1W) images, as well as pre-contrast T2-weighted (T2W) imaging. Additional MRI features, such as diffusion-weighted imaging (DWI) and perfusion weighted imaging, can be routinely obtained at most centers with MRI capabilities. Emerging evidence supports the incorporation of these data to better define tumor physiology and provide additional valuable clinical tools capable of identifying high risk subgroups as well as early predictors of response to therapies. Further, novel advanced molecular and pathophysiologic characterization of PCNSL provides insights into promising targeted therapeutic approaches. However, significant institutional imaging variation and inconsistent clinical trial reporting diminishes the reliability, reproducibility and eventual translation in day to day management of patients with PCNSL. Here we review established neuroimaging concepts and provide an overview of published literature about novel imaging techniques that may improve diagnosis and response assessments. Finally, we highlight the need for standardization of image acquisition, post-processing, and incorporation of novel imaging biomarkers in early phase PCNSL clinical trials.

Artery of Huebner stroke chameleon presenting as central nervous system lymphoma: a case description

“…Indeed, subacute stroke may still present diffusion restriction together with contrast-enhancement due to blood-brain barrier damage. Decreased levels of NAA and choline peak at MR spectroscopy is not atypical for cerebral infarction and can be also observed in CNS lymphoma which usually presents a high peak of choline ( 5 , 6 ). The overlapping imaging appearance between CNS lymphoma and stroke was another important cause of misclassification in the present case.…”

A cerebral lymphoma mimicking a meningioma: case report

“…MRI plays an important role in the differential diagnosis, which is made primarily with glioblastoma, the difference between which is made by the heterogeneous nature of the enhancement with a central necrotic zone in high-grade glioma, as well as a hyperintense signal on ADC, and the fact that cortical involvement is more frequent than in lymphomas 9 .…”

Pathology and new insights in central nervous system lymphomas

“…The typical locations are in the cerebral hemispheres (38%), deep brain region such as thalamus and basal ganglia (16%), corpus callosum (14%), and periventricular region (12%) or cerebellum (9%). Spinal cord involvement is exceptional [3,22,[24][25][26][27]. The preferential location of PCNSLs for white matter of the cerebral hemispheres and deep brain regions could be explained by the affinity of B-cell tumor cells for white matter constituent MPLZ1, MBP, and MOBP proteins, as explained above [3,19].…”