FIG. 3.

High-grade oligodendrogliomas and astrocytomas have an increased percentage of Ki-67⁺ tumor cells. A: Representative image of Ki-67 expression in a field with ×400 magnification. B and C: Ki-67 expression in tumors was assessed in noncontiguous images (n = 10 images/sample), and the average percentage of Ki-67 expression was calculated and graphed for both low- and high-grade oligodendrogliomas (B; high grade, n = 4; low grade, n = 2) and astrocytomas (C; high grade, n = 3; low grade, n = 2). The degree of Ki-67 expression trended in favor of high-grade tumors but did not reach statistical significance at this level of power (p = 0.09 for oligodendrogliomas, p = 0.2 for astrocytomas on unpaired t-testing). ns = not statistically significant; * indicates glioblastoma.