Fig. 2

Morphologic, BRAF-VE1 expression, and CNS radiographic features of BRAF V600E CNS-JXG neoplasm. Various histiologic patterns in one lesion including: a Epithelioid histiocytes (h&e) with b strong (3+) diffuse BRAF-VE1 staining of histiocytes c Plump, pale histiocyes with d moderate (2+) diffuse BRAF-VE1 staining including some foamy histiocytes. e More abundant foamy/xanthomatous histiocytes with f variable moderate (2+) to weak (1+) to focally BRAF-VE1 negative xanthomatous histiocytes, and g fibrohistiocytic areas with only weak (1+) BRAF-VE1 staining in focal histioyctes with others negative. Original magnifications at 400x. i-l. MRI imaging showing i T1 axial with contrast pre-biopsy with dominant focal enhancing lesion in the right frontal lobe (white arrow) and j status post-excisional biopsy. k T2 axial with extensive confluent, nearly symmetric white matter T2 hyper-intensity throughout the cerebral hemispheres, with a posterior predominance, and a mottled appearance (black arrows) and dominant right frontal lobe lesion (white arrow), l status post excisional biopsy with a small amount of CSF fluid in the surgical bed and peripheral enhancement along the surgical tract (white arrow) with innumerable nodular mottled T2 hypo-intensities throughout a background of diffusely abnormal hyper-intense T2 white matter abnormalities in the bilateral cerebral hemispheres (black arrows)