Introduction: Oligodendrogliomas are not common intracranial neoplasms. We retrospectively reviewed all of the gliomas operated in Ghaem Hospital between the years 1981 and 2000 and found only 35 cases of oligodendrogliomas (7.6% of total gliomas). survival analyses were performed on possible prognostic factors including: patient age and sex, presence of seizure, site, size, side, and treatment(extent of surgical resection, radiation dose, chemotherapy). Materials and Methods: Thirty-five patients with supratentorial oligodendrogliomas consisting of 27 males (77.1%) and 8 femals (22.9%) ranging in age from 4 to 68 years (mean age 36.9 years). Seizures were present in 20 patients (57%), headache in 20 patients (57%), vomiting and papilledema in 15 patients (43%), hemiparesis in 12 patients (34.3%). The surgical treatment of the 35 patients included gross total removal in ten patients (28.8%)and subtotal removal (including one patient who had only a biopsy) in 25 patients (71.2%). All patients had subtotal resection received postoperative radiation(median5000 rad), in patients whose tumors were progressed (ten patients) received further surgery and chemotherapy treatment were necessary. Result:Thirty-five patients with supratentorial oligodendrogliomas underwent surgery plus postoperative radiation and chemotherapy between the years 1981-2000. The median survival time and the 5-10 and 15 year survival rates for these 35 patients were 5.6years,54%, 34%, and 24%. Conclusion: Patients with pure oligodendrogliomas had better median survival time, approximately 5.6 years, respectively, compared with 3.2 years for those anaplastic oligodendrogliomas. The ten patients who nderwent gross total resection of their timors had a better median survival time compared with the 25 patients who had subtotal resection. Patients with partially resected lesions appeared to benefit from postoperative radiotherapy. The median survival period after subtotal tumor resection was better than patients without radiotherapy.
