Fig. 2

Morphologic spectrum of the 3 DIPGs across infratentorial and supratentorial foci. H&E and IHC with Ki-67, histone H3-K7M, PTEN and p53 antibodies of selected sections indicated by numbers and anatomic locations. The columns correspond to each case, with two central columns shown for F10. L, left; R, right; Pyr decuss, pyramidal tract decussation; LGB, lateral geniculate body; GP, globus pallidus; periV, periventricular; CC, corpus callosum. Blue arrowheads and black, red, green and yellow arrows indicate mitotic figures, microvascular proliferation, leptomeningeal spread, subventricular ependymal cell proliferation, and foamy macrophages, respectively. Among other features, note various neoplastic cell morphologies, supratentorial involvement for all tumors, brisk mitotic activity in multiple F5 foci and in the F10 biopsy, viable striated muscle fibers in F10, most likely at prior biopsy site (panel 9), labeling with H3-K27M antibody of F10 bi-nucleated ganglion cells (blue contour in panel 12), and PTEN expression detected in endothelial cells but not in tumor cells, in F12