PMC6400852_01
Brain magnetic resonance imaging (MRI):Rheumatoid meningitis. (A) Axial T1-weighted sequence post-gadolinium shows faint contrast enhancement of the leptomeninges and underlying gyri over the left convexity. (B) Finite areas of diffusion restriction of the left parietal cortex near the vertex on axial diffusion weighted imaging (DWI) sequence. (C) Coronal T1-weighted sequence post-gadolinium shows longitudinal right frontal leptomeningeal and faint left leptomeningeal contrast enhancement. (D) Axial DWI sequence shows new areas of restricted diffusion in the right frontal parafalcine region along with increased volume of restricted diffusion in left parietal cortex near the vertex. (E) Axial T1-weighted sequence post-gadolinium obtained 3 months following immunosuppressive therapy showing no abnormal contrast enhancement, and left frontal postoperative changes. (F) Axial DWI sequence obtained 3 months following immunosuppressive therapy and demonstrating the resolution of previously documented findings.
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Gadolinium-enhanced head magnetic resonance imaging (MRI) showed finite areas of scattered restricted diffusion and enhancement within the cortex and leptomeninges of the left hemisphere near the vertex, suspicious for meningoencephalitis (Figures 1A,B). A follow-up MRI, 4 weeks after admission, showed progression of the left-sided cortical and leptomeningeal areas of restricted diffusion and enhancement, as well as new right frontoparietal cortical diffusion restriction and leptomeningeal enhancement (Figures 1C,D). A whole-body positron emission tomography scan did not reveal evidence of an underlying malignancy. Repeat MRI 3 months after treatment initiation showed complete resolution of previous findings (Figures 1E,F), correlating with normalization of CRP levels.
Meningeal histologic sections:Rheumatoid meningitis. Representative hematoxylin and eosin (H&E) stained sections. (A) Meningothelial hyperplasia (magnification 200). (B) Necrobiotic core surrounded by palisading macrophages (magnification 200). (C) Cluster of inflammatory infiltrate cells consisting mainly in small lymphocytes, mixed with few plasma cells and histiocytic cells (magnification 400). (D) Diffuse meningeal inflammatory infiltrate (magnification 400).
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Hematoxylin and eosin (H&E) stained sections demonstrated meningothelial hyperplasia (Figure 2A) with acute and chronic inflammation associated with fibrosis and entrapment of the underlying brain parenchyma, which showed evidence of chronic gliosis. The most striking feature was the presence of classical zones of palisading necrobiosis (Figure 2B). The chronic inflammatory aggregates consisted in reactive CD3 positive T cells with fewer number of CD20 positive B lymphocytes, as well as CD68 positive macrophages and CD138 plasma cells with no evidence of light chain restriction (Figures 2C,D).