In the past, craniotomy was often performed for huge pituitary adenomas (>4 cm in diameter) because of the small nasal cavity, restricted field of vision and limited operating space, and it was impossible to remove the whole tumor under direct vision, while too much tumor remained and easily caused postoperative bleeding, which often required another craniotomy with high risk and high mortality. However, craniotomy also faces the disadvantages of high surgical trauma, high risk and slow recovery, which not only doctors are not willing to take risks, but also patients are not easy to accept. With the improvement of medical technology and the advancement of surgical related instruments, especially the development of neuroendoscopy in recent decades, as the technology of neuroendoscopic pituitary tumor surgery gradually matured, transnasal surgery for huge pituitary adenomas became safer and better. After successfully completing hundreds of cases of neuroendoscopic transnasal pituitary tumor resection, I have encountered a part of successful experience of transnasal surgery for huge pituitary tumors in recent years. Let’s share it. 1 The cases selected in this group were all patients with giant pituitary adenomas (>4 cm in diameter), both male and female, aged 35-64 years. The clinical manifestations were headache and vision loss; the maximum diameter of the tumor (4.2 cm-5.8 cm); all patients had tumor involvement in the intra- and supra-anterior saddle and expansive growth into the three ventricles. All patients were put under general anesthesia in the supine position with the head slightly tilted back. All patients were drained by lumbar puncture tube before surgery, and the face and nasal cavity were routinely disinfected. The anterior inferior wall of the pterygoid sinus is revealed, the opening of the pterygoid sinus is enlarged with a grinding drill, and the septum of the pterygoid sinus is removed. When the tumor cavity is large enough, the endoscope can enter the intra-, supra- and even intra-three-ventricular ventricles, and remove the residual tumor under the direct view of the endoscope, and try to gently remove the tumor with the suction device and avoid scraping with the spoon to protect the residual pituitary tissue. After the tumor was removed, the tumor cavity was directly connected with the three ventricles and the lateral ventricles, and the intracerebroventricular cavity was avoided to be filled with hemostatic material as much as possible, and the saddle was filled with artificial dura and a large piece of autologous fat. All patients except one had their tumors completely removed and their postoperative symptoms were significantly improved. All patients had different degrees of transient increase in urine volume after surgery, which improved after treatment with posterior pituitary hormone, and all patients had normal urine volume at the time of discharge. No cerebral crest fluid nasal leakage and intracranial infection occurred, and no tumor recurrence was seen on review. There was no recurrence of tumor on review, and there was no surgical death in this group. 4. Discussion: Neuroendoscopic transnasal pterygoid approach for pituitary tumor is an ideal procedure for pituitary tumor removal because it reveals the structures in the saddle area well, has a high rate of complete tumor resection, is less traumatic, has fewer complications, and the patient recovers quickly. Compared with the traditional transnasal butterfly surgery, this procedure also has the shortcomings of limited operating space, inconvenient use of microscopic instruments and easy contamination of the endoscopic lens, which requires the operator to have solid knowledge of endoscopic anatomy and skillful surgical techniques. For the surgery of huge pituitary adenoma protruding into the three ventricles, we have the following experiences: 1. Although the tumor is huge and protrudes into the three ventricles, it is not very invasive and generally the wall of cavernous sinus is relatively intact, so it can be easily removed completely. 2. Pituitary tumors that can easily invade into the three ventricles are generally soft in texture and can be removed gradually by suction, so it is easier to be removed. 3. 4. Preoperative drainage by lumbar puncture can reduce the difficulty of surgery caused by premature saddle septal descent, or cut open the saddle septum to release part of the cerebral crest fluid, which can facilitate further resection of the tumor that breaks through the saddle septal foramen and develops upward. 5. Since the operative cavity communicates directly with the ventricle, there is a greater chance of postoperative cerebral crest fluid leakage, which requires careful intraoperative repair in layers. The saddle base, tipped nasal septum mucosal flap is an important skull base repair material. In conclusion, if the surgeon has several hundred cases of neuroendoscopic pituitary tumor resection experience, especially after mastering the two-person, four-hand operation experience, and after fully communicating with the patient, transnasal surgery can be considered. Although the surgical risk is significantly higher compared with smaller pituitary tumors, it still has the advantages of minimally invasive surgery, fast postoperative recovery and fewer complications compared with open surgery.