Fig. 2

Histopathological and ultrastructural features. a-c An ependymal component admixed with subependymal features and microcalcifications (case #6, HPS, magnification × 60 for a, magnification × 400 for b-c). d Well-demarcation of the tumor from adjacent brain parenchyma (case #4, HPS, magnification × 200), confirmed using neurofilament staining (e, magnification × 100). f Monomorphous cells with small to medium-sized round nuclei and eosinophilic granular bodies (case #4, HPS, magnification × 400). g Frequent microcystic changes (case #6, HPS, magnification × 400). h Microcystic changes with myxoid substance, and eosinophilic granular bodies (case #8, HPS, magnification × 400) positive with PAS staining (case #8, insert, magnification × 400). i Hemorrhagic modifications with siderophages (case #4, HPS, magnification × 400). j Diffuse GFAP immunoexpression (case #8, magnification × 400). k Diffuse GFAP immunoexpression including in microcystic component (case #4, magnification × 400). l No immunopositivity for Olig2 (case #4, HPS, magnification × 400). m No immunopositivity for SOX10 (case #4, HPS, magnification × 400). n EMA immunoexpression with dot-like or micro-lumens (case #4, HPS, magnification × 400). o MIB-1 labeling index was low, ranged from 1% (case #8, HPS, magnification × 400). Black scale bars represent 500 μm (a), 50 µm (b-c, and f-o), 100 µm (d) and 250 µm (e) HPS: Haematoxylin Phloxin Saffron.