Fig. 1
T1-weighted MRI pre- (a, c) and post-contrast (b, d) demonstrated bilateral tumors involving the right and left frontal lobes. Right frontal tumor showed nodular contrast enhancement; left frontal tumor was ill-defined with intrinsic calcifications and no definitive enhancement. Right frontal tumor was comprised of gemistocytic astrocytes (e) and was positive for f IDH1-R132H, with g loss of ATRX expression, and h low expression of p53. Left frontal tumor was consistent with oligodendroglioma (i), was positive for j IDH1-R132H, with k retained ATRX expression, and l low expression of p53. Neither tumor demonstrated mitotic activity, microvascular proliferation, nor necrosis (×400, all panels). Right frontal tumor (m) had multiple losses of 3p26.2–26.3, 11p12–15.5, 11q25, 12q12–24.31, and Yq11.21–11.23, multiple gains of 7p11.2–22.3, 12p13.2–13.31, and 20q12.1–12.3, mosaic gains and losses of 5q13.2–35.3, 12p13.31–13.33, 12p11.22–12.2, and 13q14.11–31.3, and cnLOH of 17p. Left frontal tumor (n) had whole arm loss of 1p, whole arm loss of 19q, mosaic loss of 13q12.11–31.3, and cnLOH of 9p