Another high power view from the same case showing atypical glial cells infiltrating the brain parenchyma. The peak incidence of gliomatosis cerebri is between the ages of 20 yrs. to 40 yrs. Given the diffuse nature of the disease, surgical resection is usually not possible. Chemotherapy and radiation therapy may stabilize the disease for sometime but are unhelpful in long-term survival. The 1-yr and 3-yr survival rates are about 50% and 25% respectively. Some cases show de-differentiation to glioblastoma.