1.What kind of tumor is pituitary tumor? What is the onset of the disease? Pituitary tumor is a benign tumor occurring in the pituitary gland, also called pituitary adenoma, which is one of the most common intracranial tumors and accounts for about 10-15% of central nervous system tumors. According to the current domestic epidemiological survey, the annual incidence rate of pituitary tumors is about 1 in 100,000; while in the United States, the annual incidence rate of pituitary adenomas is as high as 7.5 to 15/100,000. The detection rate of pituitary adenomas in the normal population at random MRI examinations ranges from 10% to 38.5% (mean 22.5%). In recent years, the incidence or detection rate of pituitary adenoma has been increasing, mainly due to the development of modern medicine and the popularity of CT or MRI, which enables early detection of pituitary adenoma patients, so the incidence has increased significantly. 2. What are the clinical manifestations of pituitary adenoma? Pituitary adenomas can be classified into prolactin type, growth hormone type, adrenocorticotropic hormone type and so on according to different endocrine types, and further classified into microadenoma, macroadenoma and so on according to different sizes. The main clinical manifestations of pituitary adenomas are divided into three main categories: (1) endocrine manifestations of different types of pituitary adenomas: (1) growth hormone adenomas: immature patients show excessive growth and even develop into giants; adults show acromegaly: facial changes, thickening of fingers and toes, rough skin, general weakness, joint pain, and hypogonadism; (2) prolactin adenomas: women mainly show amenorrhea, overflow of breast, and infertility; men show hypogonadism; and men show hypogonadism. (3) Adrenocorticotropic adenoma: clinical manifestations include centripetal obesity, full-moon face, buffalo back, purple lines on the skin of abdomen and thighs, and increased body hair; (4) Endocrine inactive adenoma: early stage patients have no special feeling, but the tumor may grow up to compress the pituitary gland and cause clinical manifestations of pituitary insufficiency. (2) Visual field disorder: early pituitary adenoma often has no visual field disorder. If the tumor grows up and extends upward to compress the visual cross, visual field defect will appear, and gradually the defect may expand to bilateral temporal hemianopia. If the tumor is not treated in time, the visual acuity may also be reduced to total blindness. If the tumor is biased to one side, it may cause monocular hemianopia or blindness. (3) Other neurological symptoms and signs: if the pituitary tumor grows posteriorly and presses the pituitary stalk or hypothalamus, it may cause polyhydramnios; if the tumor grows laterally and invades the wall of cavernous sinus, it may cause nerve palsy of the locus coeruleus or adductor nerve; if the tumor grows upward through the saddle septum to the ventral part of frontal lobe, it may cause psychiatric symptoms; if the tumor grows posteriorly and obstructs the anterior part of the third ventricle and interventricular foramen, it may cause headache and vomiting, etc. If the tumor grows backward, it may compress the brainstem and cause coma, paralysis or ankylosis of the brain. 3.Treatment measures of pituitary adenoma: The treatment methods of pituitary adenoma include internal conservative treatment and surgical treatment. Surgical treatment is mainly applied to large adenomas and small adenomas for which medical treatment is ineffective. Since pituitary tumors are located at the junction of the base of the skull and the top of the nasal cavity, the surgical treatment of pituitary tumors has improved significantly from the early days when only craniotomy was possible to remove the lesion to recent years when nasal surgery is possible. The nasal cavity is a natural cavity, and due to the small size of the nasal cavity and the irregular structure of the internal turbinates, the transnasal surgical resection of pituitary tumors used to be performed through the nasal septum under the microscope, which required the use of a spreader to fracture and open the nasal septum, resulting in relatively poor surgical exposure, destruction of the nasal cavity structure, trauma, and the need to plug the bilateral nostrils to stop bleeding. Removal of the filling is also likely to cause rebleeding of the nasal cavity, and in the long term, complications such as nasal septal perforation, nasal infection and mucosal atrophy often occur. At present, the most advanced international method is “neuroendoscopic pituitary tumor resection via single nostril minimally invasive approach”. This procedure does not require artificially “excavating” a surgical channel. It takes full advantage of the neuroendoscopic approach, using the natural access to the nasal cavity to provide a more spacious surgical field and a larger operating angle. The appeal and advantage of the neuroendoscope also lies in the ability to view the surgical area up close under good illumination. When a conventional microscope is used for pituitary tumor surgery via the nasal butterfly, its illumination principle determines that it can only “look across the shore”, and there are many dead spots for observation, and the surgery relies more on the surgeon’s sense of touch. The neuroendoscope, however, can directly observe the surgical area “behind the enemy’s back”, and with its unique wide-angle field of view similar to that of a “fish eye”, the tumor features can be clearly seen, and the tumors hidden in the corners can be revealed, thus ensuring complete, minimally invasive and safe tumor removal. This ensures complete, minimally invasive and safe tumor removal. Since there is no need to use nasal speculum to dilate the nasal cavity, the operation is less invasive, more comfortable for the patient and quicker to recover after surgery. It not only greatly shortens the patient’s hospitalization date, but also minimizes the patient’s hospitalization cost. 4. Endoscopic surgery: The neurosurgery department of the hospital is one of the first units in China to carry out neuroendoscopic surgery. Recently, the most advanced German Storz neuroendoscope and full HD surgical camera system have been introduced. Our department has accumulated rich experience in removing pituitary tumor by using “neuroendoscopic minimally invasive approach through single nostril”. “Minimally invasive neuroendoscopic surgery for pituitary tumor is a new technique of minimally invasive neurosurgery with small trauma, easy operation and good treatment effect.