Primary diffuse large B-cell lymphoma of the CNS, with a "Lymphomatosis cerebri" pattern

We describe an unusual case of lymphomatosis cerebri in a middle-aged lady presenting with rapid-onset dementia. The lymphomatous infiltrate, instead of forming mass lesions, percolated throughout the brain parenchyma, which is often missed on a stereotactic biopsy and hence warrants caution and awareness about this entity. The nonspecific symptoms at presentation and a variable picture at imaging make this entity diagnostically challenging.

Imaging study of lymphomatosis cerebri characterized by diffuse lesions of bilateral cerebral white matter / 中华神经科杂志

Objective:To investigate multimodality imaging characteristics and clinical features of lymphomatosis cerebri (LC) and reasons for misdiagnosis,with the goal of potentially facilitating an early and accurate diagnosis for this often-missed disease.Methods:Clinical data and cerebral multimodality imaging findings from 11 patients with LC proven basing on pathology in the Affiliated Hospital of Guizhou Medical University from November 30, 2011 to December 28, 2020 were retrospectively extracted, analyzed, and reviewed in combination with the literatures.Results:The common presenting symptoms with subacute onset included cognitive decline (8/11), gait disturbance (9/11), and behavioral disturbance (5/11). Test of cerebrospinal fluid showed that the number of cells and the level of protein increased (8/10), the sugar content (2/10) and chloride (4/10) decreased. The imaging manifestations of 11 patients with LC were diffuse lesions of bilateral cerebral white matter in the both deep and lobar lesion distribution, involving the cerebral cortex and subcortical white matter in eight cases (8/11), basal ganglia in seven cases (7/11), thalamus in five cases (5/11), cerebellum in six cases and brain stem in six cases (6/11). All 11 patients showed equal or slightly low-density shadows on CT plain scan and slightly longer T 1WI and T 2WI signals on magnetic resonance imaging. Six cases (6/11) had no obvious enhancement in the early stage, and five cases and six follow-up cases showed heterogenous spots, patches, nodules or clusters of distinct enhancement. Diffusion-weighted imaging showed non restricted diffusion in nine (9/11) cases initially diagnosed, and restricted diffusion in two cases (2/11) and nine follow-up cases, which were hyperintense on diffusion-weighted imaging and hypointense on apparent diffusion coefficient maps. Five patients (5/5) presented a marked decrease in N-acetyl aspartic acid (NAA)/creatine (Cr) and increase in choline (Cho)/Cr on hydrogen proton magnetic resonance spectrum, including an increase in lipid/Cr in three cases. One case (1/3) showed no abnormal increase in lesion metabolism, and two cases (2/3) showed slightly increased uptake on positron emission tomography/CT. Conclusions:Diffuse bilateral cerebral lesions especially in deep and lobar region, without enhancement or with patchy enhancement, marked decrease in NAA/Cr and increase in Cho/Cr and Lip/Cr are suggestive of LC. Misdiagnosis may be mainly due to insufficient understanding and improper brain biopsy.

Modern techniques of magnetic resonance in the evaluation of primary central nervous system lymphoma: contributions to the diagnosis and differential diagnosis

Abstract In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence. This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease.

Lymphomatosis Cerebri

Lymphomatosis cerebri is considered a diffuse form of primary central nervous system lymphoma and very rare. It is not well recognized and may be misdiagnosed with infiltrating tumors, degenerative disorders, ischemic diseases, and infectious diseases developed in the brain. Awareness of the possibility of this rare disease and early biopsy are required for differential diagnosis and preventing poor clinical outcomes. We report a case with lymphomatosis cerebri who presented with rapid neurological deteriorations and review the relevant literatures.