ABSTRACT
We describe a case of primary malignant melanoma in the fourth ventricle treated with surgery and fractionated high dose radiotherapy. A 27-year-old man was referred to our institution due to drowsy mentality, dysconjugated gaze, and pupil dilatation following vertigo and posterior neck pain. Preoperative magnetic resonance images revealed a fourth ventricular tumor extending to C2 level. The mass was high-signal intensity on T1-weighted image, low- on T2-weighted and homogeneous strong enhancement. Extraneural focus of primary site was not found. After grossly total removal in two staged operations, fractionated high dose radiotherapy was given(6300 cGy, 180cGy X 35 fraction). No tumor recurrence was seen for 12 months after operation. Aggressive treatment involving operative total tumor removal and combined radiotherapy is considered to increase the life span of the patient even with this type of tumor.