Oligoastrocytomas are tumors located mainly in supratentorial subcortical brain areas showing composite histological features and including cells similar to oligodendrocytes or astrocytes.
Oligoastrocytomas and pure oligodendrogliomas constitute a subgroup of brain tumors receiving increased attention because of reports of chemosensitivity and of favorable survival rate when compared with astrocytomas. This is also reflected in the increasing rate of diagnosis of tumors with an oligodendroglial component rising from about 5 % in the past decade to approximately 15 % in present years.
The morphological borderlines between astrocytomas, oligoastrocytomas, and oligodendrogliomas are difficult and controversial issues. However the accurate distinction between these tumors has important prognostic and therapeutic implications. Patients with pure oligodendrogliomas are more likely to respond to chemotherapy and have a longer survival than...