Higher magnification from the previous case showing occasional atypical glial cells with mildly enlarged hyperchromatic nuclei diffusely infiltrating through brain parenchyma. This patient presented with headaches, lethargy, and progressive loss of congnitive functions. Diagnosis was made on autopsy. The diagnosis of gliomatosis cerebri on MRI and CT scan can be quite difficult because the lesion is usually ill-defined and isodense to the normal brain parenchyma. There may be slight asymmetry on CT or MRI images, but mass effect and enhancement with contrast are minimal.