Clinical value of abnormal findings on brain magnetic resonance imaging in patients with intravascular large B-cell lymphoma.

To investigate the prevalence and clinical value of abnormal findings detected via brain magnetic resonance imaging (MRI) in patients with intravascular large B-cell lymphoma (IVLBCL), we identified 33 patients with IVLBCL pathologically diagnosed and evaluated with pretreatment brain MRI. Abnormal findings on brain MRI were categorized into four patterns: (1) hyperintense lesion in the pons on T2-weighted imaging (T2WI), (2) nonspecific white matter lesions, (3) infarct-like lesions, and (4) meningeal thickening and/or enhancement. Abnormal cerebral findings were detected in 29 patients (87.9%). Hyperintense lesion in the pons was the most common finding (n = 19 (57.6%) patients), followed by nonspecific white matter lesions (n = 14 (42.4%) patients), infarct-like lesions (n = 8 (24.2%) patients), and meningeal thickening and/or enhancement (n = 4 (12.1%) patients). Impaired consciousness was seen in most of the patients with infarct-like lesions (87.5%) but less frequently in patients with hyperintense lesion in the pons (47.4%). We reviewed brain MRI findings in 39 patients with diffuse large B cell lymphoma with central nervous system (CNS) involvement and/or high-risk extranodal lesions for CNS involvement as a control group. In contrast to the patients with IVLBCL, no patient had hyperintense lesion in the pons in the control group (P < 0.001). Follow-up brain MRI revealed improvement of abnormal findings in most of the patients who responded to chemotherapy. This study highlighted the diagnostic implication of hyperintense lesion in the pons on T2WI and the clinical usefulness of pretreatment brain MRI in IVLBCL even in patients without impaired consciousness.