PMC10266482_01
Radiological imaging. (A) CT of head without contrast (axial) does not show any abnormalities. (B and C) MRI of brain on 1st admission demonstrated small areas of right occipital subcortical patches of T2W (B) and FLAIR (C) bright signal. MRI of head on 2nd admission showed right parieto-occipital parasagittal subcortical and periventricular hyperintensity extending to the right side of splenium of corpus callosum on T2W axial (D), FLAIR sagittal (E) and FLAIR axial (F) sections (red arrowhead). MRI of head with contrast sagittal (G) and axial (H) sections revealing patchy nodular branching pattern of post-contrast enhancement of the hyperintense areas on T2/FLAIR. The enhancement is seen extending to the ependymal surface of occipital horn of right lateral ventricle.
IMCRJ-16-357-g0001.jpg
PMC10266482_01_IMCRJ-16-357-g0001.jpg
f0001
Brain computed tomography (CT) was reported normal (Figure 1A). T2WI and FLAIR sequences (Figure 1B and C). The patient was assessed by a neurologist and subsequently discharged on anti-epileptic medications. MRI head with contrast (Figure 1D and E) was done and showed right parieto-occipital parasagittal subcortical and periventricular areas of T2W/FLAIR hyperintensity extending to involve right side of splenium of corpus callosum and demonstrating a patchy and nodular branching pattern of enhancement on T1WI with contrast (Figure 1F-H). MRI of the brain with contrast of our patient (Figure 1) showed radiological features reminiscent of the acronym PEPPERING.
Histopathology. Microscopic examination of the biopsy specimen shows fragments of gray and white matter heavily infiltrated by inflammatory cells with significant condensation of lymphocytes (CD45+) around the blood vessels (perivascular cuffing) (A and B) as well as diffuse infiltration of the brain parenchyma by similar lymphocytes. Most of the lymphocytes are of T-lymphocytes (CD3+) (C) of the T4 subtype (CD4+) (D); while T8 subtype (CD8+) are much less (E). Another population of B lymphocytes (CD20+, 79 A+) was seen at the periphery of the T cell population (F). In addition, several clusters of foamy macrophages were seen within the lymphocytes (CD 163+) along with minor population of plasma cells (CD 138+).
IMCRJ-16-357-g0002.jpg
PMC10266482_01_IMCRJ-16-357-g0002.jpg
f0002
Stereotactic biopsy of the right occipitoparietal lesion provided multiple samples of grayish white soft tissue for histopathological analysis which revealed fragments of gray and white matter heavily infiltrated by inflammatory cells with significant condensation of lymphocytes (CD45+) around the blood vessels (perivascular cuffing) (Figure 2A and B) as well as diffuse infiltration of the brain parenchyma by similar lymphocytes. Most of the lymphocytes were of T-lymphocytes (CD3+), (Figure 2C) of the T4 subtype (CD4+) (Figure 2D); while T8 subtype (CD8+) were much less (Figure 2E). Another population of B lymphocytes (CD20+, 79 A+) was seen at the periphery of the T cell population (Figure 2F).