PMC6119690_01
Radiologic findings. Axial T2-weighted FLAIR imaging (A) demonstrates an extra-axial hyperintense mass centered within the right paramedian parietal region with a focus that appears to be inseparable from the adjacent cortex (asterisk in A,B). On the axial T1 post contrast images (B,C) the lesion is predominantly nonenhancing and hypointense, with areas of heterogeneous enhancement (arrow in B). Also noted is lateral displacement of a cortical vessel (arrow in C), suggestive of an extra-axial location of the mass. Coronal non-contrast CT imaging demonstrates a focus of coarse calcification (arrow in D) in the hypoattenuating mass.
fneur-09-00700-g0001.jpg
PMC6119690_01_fneur-09-00700-g0001.jpg
F1
Brain magnetic resonance imaging (MRI) demonstrated a right paramedian parietal region mass, ~5 x 6cm in perpendicular dimensions, with patchy areas of contrast enhancement and coarse calcification (Figure 1D).
Histologic findings. (A) Microscopic examination showed diffuse sheets of a tumor composed of relatively small cells with round-to-oval nuclei and scant-to-cleared cytoplasm. (B) GFAP was positive in a subset of tumor cells. (C) IDH1 p.R132H mutant protein immunohistochemistry was strongly positive. (D) ATRX protein wildtype expression was retained. (E) Weak expression of p53 protein. (F) Low Ki67 labeling index of 4.8%. (G) Mitotic activity (arrow) was quantified at a maximum of 2 per 10 high-power fields using phosphohistone H3 (pHH3) immunostaining.
fneur-09-00700-g0002.jpg
PMC6119690_01_fneur-09-00700-g0002.jpg
F2
H&E-stained sections showed diffuse sheets of a tumor composed of relatively small cells with round-to-oval nuclei and scant-to-cleared cytoplasm (Figure 2).