Pituitary adenomas are a group of tumors that occur from the anterior and posterior pituitary lobes and the epithelial remnant cells of the craniopharyngeal canal and account for 10% to 15% of central nervous system tumors. The vast majority of pituitary adenomas are benign tumors. Among them, PRL tumors are the most common accounting for about 50-55%, followed by GH tumors in 20-23%, ACTH tumors in 5-8%, and TSH tumors and LH/FSH tumors are less common. Non-functioning pituitary adenomas account for 20-25% of cases. Recently, several patients with pituitary tumors have been treated irregularly, resulting in hypopituitarism and lifelong dependence on hormone supplementation. The standardized diagnosis and treatment process of pituitary tumor is introduced as follows: Step 1: Endocrinology to clarify the diagnosis 1. 2.Define whether pituitary tumor secretes hormones and affects pituitary and target gland function: Check pituitary hormones, including PRLACTHTSHFSHLHGH, and evaluate target gland hormones, including adrenocorticotropic hormone, thyroid hormone (FT3FT4), sex hormone (E2PT), IGF-1, etc. 3.To clarify whether there is local compression of pituitary tumor: assessment of visual field defects, testing of visual acuity, etc. 4.Differential diagnosis of pituitary tumor 1）Neoplasm: craniopharyngioma, saddle node meningioma, Lasker’s cleft cyst, germ cell tumor, optic cross glioma, epithelioid cyst. (2) Inflammation: pituitary abscess, eosinophilic granuloma, lymphocytic pituitary inflammation, mycobacterial inflammation, tuberculous meningitis. (3) Hyperplasia: (1) Physiological: during pubertal development, pregnancy and lactation. (2) Pharmacological: Sedative and sleeping drugs for psychiatric disorders are the most obvious. Some proprietary Chinese medicines such as Six Bit Dihuang Pills can also cause hyperplasia of pituitary tissue and a significant increase in serum PRL. (3) Compensatory: hypothyroidism and hypoadrenocortical feedback cause pituitary hyperplasia. In particular, pituitary hyperplasia caused by hypothyroidism disappears quickly when thyroxine is supplemented. (4) Pathological: unexplained factors cause hyperplasia of pituitary tissue, which partially transforms into tumor. (4) Others: Intrasellar aneurysm, arachnoid cyst, primary vacuolated saddle, retrobulbar optic neuritis. Step 2: Treatment The treatment of pituitary tumor mainly includes surgery, medicine and radiation therapy. Individualized treatment plans need to be developed based on the size of the pituitary tumor, hormone secretion, complications and co-morbidities, the patient’s age, whether he or she has fertility requirements, and the patient’s financial situation. The treatment of pituitary tumor is a comprehensive treatment process with multi-disciplinary collaboration. 1) For pituitary prolactin-secreting tumors, more than 90% of patients (both microadenomas and macroadenomas) can control PRL levels with dopamine agonists (short-acting agents bromocriptine, long-acting agents cabergoline) to reduce the size of the tumor. Surgery is only an option for patients with prolactinomas who are allergic or intolerant to this class of drugs, have acute symptoms due to tumor compression that require emergency surgical decompression, or patients who are unwilling to undergo surgical treatment. (2) Treatment goals for patients with growth hormone-secreting tumors: eliminate tumors, reduce tumor recurrence, GH attainment, relieve clinical symptoms, preserve pituitary function as much as possible, improve patients’ quality of life and prolong their life span. Preoperative application of growth inhibitor analogues such as long-acting octreotide and somatuline can rapidly reduce the patient’s serum GH level, alleviate the patient’s symptoms, reduce the size of the tumor, and create good preoperative conditions for complete surgical removal of the tumor. Patients with GH tumor whose GH and IGF-1 levels are still elevated after surgery should be given octreotide or dopamine agonists as adjuvant therapy; for those who have poor results with drug therapy, radiation therapy can be considered. (3) ACTH tumors are also treated with ketoconazole or other adrenal corticosteroid synthase inhibitors to inhibit the excessive production of cortisol and to relieve clinical symptoms. 2.Radiotherapy Pituitary tumors are adenomas, which are less sensitive to radiotherapy. 70%-80% of patients have reduced pituitary function after radiotherapy, which reduces the quality of life of patients, so radiotherapy is only suitable for patients with surgical residuals, those who cannot tolerate surgery, those who are not sensitive to drugs, and those who have co-morbidities that cannot be treated with surgery or drugs. 3.Surgical treatment Currently, surgery is preferred for most GH tumors, ACTH tumors, TSH tumors and non-functional macroadenomas. Surgical methods include transsphenoidal sinus, craniotomy and gamma knife. Step 3: If surgery is needed, a neurosurgeon will consult with the patient to determine the surgical plan and perform the surgery. Step 4: Postoperative pathology is performed with routine and hormonal immunohistochemical staining to clarify the diagnosis. Step 5: After surgery, return to the endocrinology department to assess pituitary function, determine whether relevant hormone replacement therapy is needed, and follow up with regular review. Special reminder: 1. Drug therapy is preferred for pituitary prolactin-secreting tumors. 2. Patients with pituitary tumors and hyperprolactinemia need to check thyroid function to exclude hypothyroidism. Hypothyroidism can cause pituitary hyperplasia and elevated prolactin. When supplemented with thyroxine, pituitary hyperplasia disappears quickly, so please do not operate for treatment.