Endoscopic Trans-Sphenoidal Resection of a Giant Pituitary Neuroendocrine Tumor with Third Ventricle Invasion and Obstructive Hydrocephalus: Surgical Anatomy and Two-Dimensional Operative Video.

Giant pituitary neuroendocrine tumors (G-PitNETs) are relatively rare lesions, defined as larger than 4 cm in maximum diameter, and being about 6-10% of all pituitary tumors1. Therapeutic options almost always rely on surgical resection in such cases, with the endoscopic endonasal trans-sphenoidal route being nowadays the gold standard of treatment among the spectrum of possible approaches. The aims of surgical treatment can be summarized as (1) maximizing the extent of resection and (2) preserving/ameliorating neurological and pituitary functions1-3. However, besides their considerable volume, G-PitNETs usually share a complex morphology which makes a gross total resection potentially challenging and often requires the use of extended approaches4-7. In this operative video, we present the case of a 59-year-old male patient who presented to our Institution complaining of visual impairment, gait ataxia, urinary incontinence, and bitemporal hemianopsia. Preoperative imaging revealed a giant sellar-suprasellar lesion associated with third ventricular invasion and obstructive hydrocephalus. Given the patient’s symptoms, and the tumor’s radiological characteristics, surgical treatment was proposed, and an extended endoscopic trans-sphenoidal approach was then performed. Regional anatomy and surgical technique have been extensively described. Postoperative magnetic resonance imaging demonstrated the gross total resection of the lesion, which was histologically confirmed, as a G-PitNET. The patient did not experience any neurological deficits or major complications. The patient consented to the procedure and to the publication of his images.