[Clinically Non-Functioning Pituitary Adenoma/Pituitary Neuroendocrine Tumor (PitNET)].

Clinically non-functioning pituitary neuroendocrine tumors (PitNETs), the most common subtype of pituitary tumors, are frequently detected because of mass effects, such as visual impairment and incidental findings. In the World Health Organization classification in 2022, pituitary adenomas have been termed PitNETs, reflecting their biological diversity. This review summarizes the diagnostic evaluations, surgical indications, pathological characteristics, and surgical techniques for non-functioning PitNETs on endoscopic endonasal transsphenoidal surgery (eTSS). Preoperative assessment requires a meticulous endocrine evaluation and detailed magnetic resonance imaging to define tumor extension and invasion, and its relationship with the surrounding neurovascular structures. Surgery is the first-line treatment for symptomatic tumors. Asymptomatic patients with radiological risk factors were selected. Pathologically, non-functioning PitNETs comprise heterogeneous subtypes defined by transcription factors, including gonadotroph, silent corticotroph, and Pit-1 lineage tumors, with some exhibiting aggressive behavior. Technical aspects of eTSS, including intrasellar and extracapsular tumor removal and extended approaches for suprasellar extension, are discussed, highlighting safe and effective tumor resection. Individualized surgical strategies based on tumor characteristics are essential to achieve optimal outcomes.