Endoscopic transventricular biopsy in brainstem diffuse midline glioma: how I do it

Brainstem diffuse midline gliomas represent infiltrative and rare pediatric tumors with a dismal prognosis. Surgical biopsy is emerging as a valid technique to define diagnosis and molecular markers for future targeted therapies.We describe the key steps of an endoscopic trans-ventricular biopsy of a brainstem diffuse midline glioma and associated ventriculomegaly. The relevant surgical anatomy along with an illustrative video is described.The endoscopic third ventriculostomy combined with a punch biopsy of a brainstem diffuse midline glioma associated with ventriculomegaly represent a feasible and low-risk procedure to simultaneously treat incipient hydrocephalus and molecular diagnosis for future treatment and research.