Primary intracranial peripheral primitive neuroectodermal tumor/Ewing's sarcoma presenting with acute intracerebral hemorrhage.

OBJECTIVE: To report two cases of intracerebral hemorrhage due to primary intracranial peripheral primitive neuroectodermal tumor (pPNET)/Ewing's sarcoma (ES) and review of related literatures. MATERIAL: Two cases of 17-year-old patients presented with acute increased intracranial pressure one of which also had left hemiparesis. METHOD: On neuroimaging studies, the first patient had an intraparenchymal hematoma with a size of 4 cm at the right fronto-parietal junction adjacent to tumor infiltrating the superior sagittal sinus. The second patient had a large left temporal tumor with intraventricular hemorrhage. Both patients underwent craniotomy with complete removal of tumor and hematoma. RESULTS: Pathological examination in both cases revealed numerous small round tumor cells with stippled chromatin pattern and scanty cytoplasm. Tumor cells strongly expressed CD99. Vimentin immunoreactivity was observed. The final diagnosis of pPNET/ES was rendered. There was no evidence of extracranial disease in both cases. Both patients were doing well without evidence of recurrent disease at 12 and 24-month follow-up respectively. CONCLUSIONS: Peripheral primitive neuroectodermal tumor (pPNET)/Ewing's sarcoma (ES) is a malignant small round cell tumor, commonly arising in soft tissue of the trunk and lower extremity. Those occurring in the intracranium are rare, and most patients present with progressively increased intracranial pressure and/or cranial nerve deficit. The occurrence of intracerebral hemorrhage due to primary intracranial pPNET/ES is exceedingly rare. The role of adjuvant therapy in this condition is yet to be investigated.