OUTLINE: This is an open label pilot study. Patients receive oral hydroxyurea tid. A course of hydroxyurea consists of 4 weeks of therapy. On day 28, after the first course of treatment, tumor size is analyzed by MRI. If no reduction in tumor size is seen on day 28, hydroxyurea dose is increased. If a CR or PR is demonstrated, patients continue on the same treatment at the original dose. MRI evaluation is again taken on day 56 of treatment. Patients with progressive disease at this evaluation are considered to have no treatment response.