Primary Intracranial pPNET/Ewing Sarcoma: Diagnosis, Management, and Prognostic Factors Dilemma-A Systematic Review of the Literature.

Background: Ewing sarcoma (ES) is a malignant bone tumor that is most commonly observed in the long bones, the pelvis, and the chest. Primary intracranial localization is extremely rare.

Objective: In the aim of identifying the prognostic factors of this rare localization, we conducted a systematic review of the literature for patients with primary intracranial peripheral primitive neuroectodermal tumor/ES.

Methods: A complete MEDLINE search was undertaken for all articles reporting data for primary intracranial peripheral primitive neuroectodermal tumor/ES. We divided the patient population into 2 groups: group I, patients who were free of disease; and group II, patients who died or had uncontrolled disease at the last available follow-up. We conducted a comparative statistical analysis of data between the 2 groups.

Results: A total of 48 patients were included in the review. There were 32 patients in group I and 12 in group II. Fifty percent of tumors in group II and only 16% of tumors in group I were infratentotorial (P = 0.03). Signs of bone involvement were observed in 19% of patients in group I and 54% in group II (P = 0.03). Total removal was accomplished in 29% of patients in group I and in no patients in group II (P = 0.03). Radiotherapy was performed in 73% of patients in group II and 81% in group I (P = 0.43). Chemotherapy was administered in 36% of patients in group II and 74% in group I (P = 0.03).

Conclusions: Infratentorial localization and the presence of bone involvement were associated with poor prognosis; Surgery seems to be a predictive factor of prognosis; radiotherapy and chemotherapy must be performed whenever the tumor is not totally removed.