**2. Epidemiological and clinical aspects**

Diffuse astrocytic tumors comprise approximately 60% of primary intracranial tumors. These tumors can arise at any age in children and the very elderly, although incidence increases substantially with advancing age. The median age is 30–40 for diffuse astrocytoma, 40–50 for anaplastic astrocytoma, and 50–60 years for glioblastoma. Older patients are also more likely to have higher grade gliomas, especially glioblastoma. The last one is the most frequent neoplasm in this category, accounting for approximately 80% of the diffusely infiltrative astrocytomas [11, 12].

The clinical presentation of the diffuse astrocytomas varies according to the sites of involvement and the rate of growth. The most common clinical symptoms are new-onset seizures, changes in behavior, motor deficits, and sing/symptoms of increased intracranial pressure (headache, nausea, vomiting, and papilledema). High-grade astrocytoma tend to have a short history with rapid progression, whereas low-grade astrocytoma are more indolent, often with insidious onset and a long, protracted clinical course [11, 12].
