Gross total removal of adult brainstem glioma--two case reports.

Two adult patients with brainstem glioma were successfully treated surgically. A 37-year-old male had a dorsally exophytic pontine glioma developing from the fourth ventricular fundus, and another 27-year-old male an intrinsic nodular mesencephalic glioma. Preoperative magnetic resonance imaging clearly visualized the tumor margin in both cases, and showed the relationship between the tumor and brainstem structure accurately. The tumors were radically excised using intraoperative evoked potential monitoring, ultrasonic surgical aspirator, and microsurgical techniques. Surgery is indicated when the tumor margin in the brainstem and adjacent region is clear, and the approach is possible without affecting the functional prognosis.