Figure Sagittal and axial T1-weighted MR images, hematoxylin and eosin-stained specimen, and S100-stained specimen

Sagittal (A) and axial (B) T1-weighted MR images revealing a contrast-enhancing extra-axial mass lesion with indentation of the cortex, dural thickening, underlying vasogenic edema, and a projection into an intersulcal region. Hematoxylin and eosin-stained specimen (C) shows a lymphohistiocytic infiltrate with histiocytes demonstrating emperipolesis (lymphocytophagocytosis). S100-stained specimen (D) shows histiocytes positive for S100.