Gliosarcoma, a subtype of Glioblastoma, is a primary biphasic tumor of the central nervous system composed of both gliomatous and sarcomatous elements. Usually accruing in the cerebral cortex, Gliosarcoma mainly involves the temporal and frontal lobes. The incidence of Gliosarcoma is 2-8% of all brain tumors and accounts for less than 2% of glioblastomas, thus representing an exceptionally rare neoplasm. Despite the low incidence of this malignant neoplasm, Gliosarcoma has the potential to metastasize through blood to the lungs, liver and lymph nodes. Due to its aggressivity and metastasizing potential, Gliosarcoma is associated with a low survival rate.

Several prognostic factors have been reported to be associated with Gliosarcoma, with varying degree of evidence supporting each. Unfortunately, no study reporting the incidence and epidemiological data of Gliosarcoma in the Middle East has been done. Hence, this project is the first attempt to study the epidemiology of Gliosarcoma in patients treated at the American University of Beirut Medical Center (AUBMC), and to compare it with that of the world literature in order to evaluate for prognostic factors associated with Gliosarcoma, mainly tumor characteristics, management approaches and outcomes.

This study will be a single institution retrospective cohort study based on chart review of all cases of Gliosarcoma seen at the American University of Beirut Medical Center (AUBMC), a tertiary- care hospital, over a period of 20 years (January 1st of 1995 until December 31^th 2015).

A list with the names of these patients will be obtained from the institutional tumor registry at AUBMC. Given we are studying a relatively rare exposure; the best feasible study design would be a retrospective cohort study.