[A case of the lateral ventricle lesion mimicking arachnoid cyst treated by neuroendoscopic surgery].

A 12-year-old female suffered from intermittent headache with nausea. Neuroradiologic studies demonstrated a cystic lesion in the right trigone with content like cerebrospinal fluid. The right inferior horn was isolated and increased in size. Eodoscopic fenestration was attempted using a flexible fiberscope via the inferior horn. Postoperative magnetic resonance image revealed shrinkage of the cyst and reduced size of the right inferior horn. Intermittent headache dissapeared. Neuroendoscopic treatment is a less invasive and effective therapy for intraventricular arachnoid cyst as well that in the other intracranial lesion.