Low signal intensity lesions on brain susceptibility-weighted MRI in a patient with intravascular large B-cell lymphoma.

A 71-year-old man was admitted to our hospital because of abnormal behavior and generalized convulsion. Brain MRI revealed no abnormalities upon admission. Levels of serum lactate dehydrogenase and soluble interleukin-2 receptors were significantly elevated, whereas the initial bone marrow puncture and random skin biopsy findings were non-malignant. On the tenth day of admission, brain MRI revealed dot and strip-shaped low signal intensity lesions on susceptibility-weighted images (SWI) disseminated mainly within the cerebral cortex. Administration of high dose methyl-prednisolone improved neither his condition nor these MRI findings. Ground-glass opacities within the bilateral lungs later emerged on the chest CT. The results of a transbronchial lung biopsy and second bone marrow puncture were consistent with a diagnosis of intravascular large B-cell lymphoma (IVLBCL). Despite the lack of histopathological confirmation, the low signal intensities on brain SWI in this case were also considered IVLBCL lesions, reflective of micro-hemorrhagic changes.