Seven-Year Delayed Diagnosis of a Giant Suprasellar Arachnoid Cyst Presenting With Progressive Gait Disturbance: Successful Endoscopic Ventriculocystocisternostomy-A Case Report.

Suprasellar arachnoid cysts are uncommon pediatric lesions that may cause obstructive hydrocephalus and optic pathway compromise, often with insidious clinical progression. We report an 11-year-old boy who presented with a 7-year history of progressive gait disturbance and imbalance. Neurological examination was largely normal, and visual acuity was preserved; however, fundoscopic examination revealed bilateral optic disc pallor. Brain magnetic resonance imaging demonstrated a giant cerebrospinal fluid-intensity cyst centered in the third ventricle with inferior extension into the suprasellar and prepontine cisterns, causing functional obstruction of the foramina of Monro and marked ventriculomegaly. The patient underwent endoscopic ventriculocystocisternostomy via a right frontal approach, establishing wide communication between the ventricle, cyst, and basal cisterns. Postoperatively, he remained neurologically intact with early improvement in balance. Transient hypoadrenocorticism was identified and successfully managed with hydrocortisone replacement. This case highlights the potential for delayed presentation of suprasellar arachnoid cysts with preserved visual acuity despite chronic optic pathway injury and supports ventriculocystocisternostomy as a shunt-sparing treatment option in appropriately selected pediatric patients, particularly when cyst anatomy is favorable and long-term shunt surveillance cannot be reliably ensured.