A Clinical Study on 37 Cases of Oligodendroglioma

ABSTRACT

The authors reviewed 37 consecutive cases of histologically proven oligodendroglioma who were treated at the Seoul National University Hospital, between 1979 and 1986. There was a 1.5 1 male to female ratio. The age of patients at the time of diagnosis varied between 6 and 64 years(mean 38 years), with 51% in the fourth and fifth decades. The incidence of oligodendrogliomas represented 5% of all brain tumors and 15.5% of all gliomas. All but one were located supratentorially and 54% of them involved the frontal lobe. The mean duration of symptoms prior to the surgery was 27.2 months, but seizures had a considerably longer duration of 6.4 years. The common symptoms were headache(62%), seizures(38%), and motor weakness(22%). The common neurological findings were papilledema(51%), motor dificit(24%), and change in cognition(19%). Six out of 37 cases(16%) presented as the spontaneous intracranial hemorrhage. Calcifications were detected on plain X-ray films of the skull in 19% of patients and fine vascular stains were found on carotid angiograms in 30% of the cases. Brain CT revealed calcification(57%), cyst formation(43%), low density(35%) and heterogenous contrast enhancement(35%). The important factors affecting the prognosis and the recurrence rate were (1) the extent of surgical excision, (2) postoperative radiation therapy, and (3) the pathologic grading. There was a significant difference in the recurrence rate between patients treated with postoperative irradiation and patients treated with surgery alone.