Atypical teratoid/rhabdoid tumors (AT/RT) are malignant central nervous system (CNS) tumors that represent 3% of all pediatric CNS tumors. Majority of cases have SMARCB1 gene mutations and historically carried a poor prognosis.

A 9-year-old boy was diagnosed with a third ventricle AT/RT and initially underwent endoscopic surgical biopsy. Subsequent tumor resection was completed using an interhemispheric–transcortical approach.

Surgical approaches to ventricular system must be tailored to the tumor characteristics on a case-by-case basis. We present a case using a transcortical approach for understanding of the microsurgical anatomy for safe resection of a third ventricle AT/RT.