Rosette-forming Glioneuronal Tumor: Rare Case Presented with Spontaneous Disappearance of Contrast Enhancement.

This report presents rosette-forming glioneuronal tumor (RGNT) of the tectum in a 24-year-old woman in whom spontaneous disappearance of contrast enhancement (CE) on magnetic resonance (MR) imaging was observed during 9-year follow-up period before therapeutic intervention. MR imaging obtained 9 years ago when she first visited local hospital with headaches showed a mass of the brain stem with CE. Follow-up MR imaging showed disappearance of CE without tumor growth.