Fig. 2From: Supratentorial extra-axial RELA fusion-positive ependymoma misdiagnosed as meningioma by intraoperative histological and cytological examinations: a case reportHistological, immunohistochemical, and ultrastructural findings of the dura-attached supratentorial extra-axial tumor. a–f, Low-magnification (a and d–f) and high-magnification (b, c) images of the formalin-fixed paraffin-embedded specimen stained using HE showing scattered perivascular rosettes (a), prominent fine fibrillary processes in a perivascular anucleate zone (b), mitotic cells indicated by arrows (c), microvascular proliferation (d), necrosis (e), and tumor invasion to dura marked by D (f). g, h, Immunohistochemical images with paranuclear dot-like positivity for epithelial membrane antigen (g) and membranous positivity for L1 cell adhesion molecule (h). i Transmission electron micrograph (uranyl acetate–lead citrate staining) exhibiting microvilli marked by Mv in microlumen suggesting ependymal differentiation. Bars: 100 µm in a and f, 25 µm in b and g, h, 12.5 µm in c, 50 µm in d, e, and 4 µm in iBack to article page