PMC9816224_01
Brain imaging. A Axial T2-weighted image at diagnosis, showing a left-sided tumefactive hyperintense lesion (*) surrounded by an internal hypointense (arrowhead) and external hyperintense ring (open arrow). This concentric ring appearance is attributed to areas of demyelination alternating with relatively preserved myelin (Balo-like tumefactive lesion). B Diffusion (B 800) image shows an open ring of restricted diffusion (arrowhead). C Proton MR spectroscopy with voxel localization over a new tumefactive right-sided lesion. There is an elevation of the beta,gamma-Glx peaks at 2.1-2.6 ppm region (arrows) and presence of lactate doublet (arrowhead) that suggest an inflammatory demyelinating process. Alpha decrease of N-acetylaspartate (NAA), increased choline (Cho) are non-discriminating findings. D CT shows hypoattenuation at the areas of known white matter lesions (arrows)
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PMC9816224_01_10072_2022_6396_Fig1_HTML.jpg
Fig1
One tumefactive lesion exhibited a concentric ring appearance, an open ring diffusion restriction pattern, and thin ring enhancement, consistent with a Balo-like lesion (Fig. 1A, 1B). One month later, the patient developed left hemiparesis which gradually evolved into motor disability, while new lesions at the right periventricular white matter (Fig. 1C) and at additional sites were consistent with MS, according to space and time international criteria. Instead, computed tomography (CT) revealed hypoattenuation at the areas of abnormality (Fig. 1D), excluding cerebral lymphoma and supporting the diagnosis of TMS.