 It is estimated that approximately 2.1% of all glioblastomas are gliosarcomas.Although most gliomas rarely show metastases outside the cerebrum, gliosarcomas have a propensity to do so, most commonly spreading through the blood to the lungs, and also liver and lymph nodes.Gliosarcomas have an epidemiology similar to that of glioblastomas, with the average age of onset being 54 years, and males being affected twice as often as females.