Glioma is the most common malignant brain tumor, and terahertz (THz) spectroscopy has shown potential for pathological diagnosis. Previous anisotropy studies using THz time-domain spectroscopy (THz-TDS) were limited to animal tissues such as porcine fascia and muscle. Here, we report the first verification of isotropy in human glioma pathological tissues. Tissue slices from patients were analyzed at multiple rotational angles, and parameters including absorption coefficient, refractive index, and dielectric constant were evaluated. The results showed no angular dependence, and polar plots confirmed isotropic behavior. Importantly, MGMT promoter methylation status was found to influence refractive index and dielectric constant, suggesting potential molecular-level biomarkers. Optical microscopy revealed random microstructural organization as the basis of isotropy. These findings highlight the unique contribution of human pathological validation with molecular stratification, providing a foundation for the clinical application of THz technology in rapid intraoperative diagnosis.