FIG 4. A, Microscopy shows characteristic histopathologic features of ependymoma with true rosettes and pseudorosettes, perivascular orientation (hematoxylin-eosin; original magnification x 200). B, Tumor cells have abundant brown melanin pigment (arrows) in the cytoplasm that shows positivity for Masson-Fontana (original magnification x100). C, Brown melanin pigment is also present in the interstitial space of the tumor (arrows; hematoxylin-eosin; original magnification x40).