Overview Pituitary adenomas are common benign tumors that occur in populations generally at a rate of 1 per 100,000. Some reports are as high as 7 per 100,000. Among intracranial tumors, it is only lower than glioblastosis and meningioma, accounting for about 10% of intracranial tumors, and the detection rate in autopsy is 20%-30%. There is a trend of increase in recent years. Pituitary adenoma mainly harms human body from the following aspects: (1) overproduction of pituitary hormone causes a series of metabolic disorders and organ damage; (2) tumor compression makes other pituitary hormones low, causing the corresponding target gland to function low; (3) compression of structures in the pterygoid saddle area, such as optic nerve, optic nerve, cavernous sinus, basilar artery, hypothalamus, III ventricle, even involving frontal lobe, frontal lobe, brainstem, etc., resulting in the development of pituitary adenoma. Pituitary adenomas are most common in young adults and cause serious damage to growth, development, work capacity, and reproductive function, as well as a series of psychosocial effects. Since the end of the 19th century, people’s understanding of pituitary adenoma has been deepening, especially since the 1970s, with the rapid progress of modern science and technology, the development of modern endocrinology, modern pathology, modern radiology, modern neuro-ophthalmology and modern microsurgery, there are many new advances in clinical and basic research on pituitary adenoma. This has deepened the understanding of the disease and improved the diagnosis and treatment. Various endocrine cells in the pituitary gland can produce corresponding endocrine cell adenomas, causing endocrine dysfunction. The signs of endocrine hyperfunction can be seen in the early stage of microadenoma. As the adenoma grows and develops, it may compress and erode the pituitary tissue and its pituitary and peripituitary structures, resulting in hypoendocrine function, visual dysfunction and other cranial nerve and brain symptoms. Clinical manifestations of functional pituitary adenoma: 1. Prolactin adenoma: It is mainly characterized by amenorrhea, lactorrhea and infertility due to increased prolactin and decreased estrogen, also known as Forbis-Albright syndrome. 2.Growth hormone adenoma: Due to the excessive secretion of growth hormone, early microadenoma can cause metabolic disorders, resulting in a series of changes such as excessive growth of bones, soft tissues and internal organs, etc. The course of the disease is slow and progressive. 3, adrenocorticotropic hormone adenoma: due to pituitary adenoma continues to secrete too much ACTH, causing adrenal cortical hyperplasia prompting excessive secretion of cortisol, that is, cortisolism (Cushing’s Syndrome), resulting in a series of substance metabolism disorders and pathological changes, and the emergence of many clinical symptoms and signs. 4. Thyroid-stimulating hormone cell adenoma: Rare. Due to excessive TSH secretion, T3 and T4 increase, and clinical symptoms of hyperthyroidism. There are also TSH adenomas caused by negative feedback secondary to hypothyroidism (e.g., thyroiditis, after isotope treatment). The adenoma causes enlargement of the pterygoid saddle, suprasellar development, and visual dysfunction. 5. Gonadotropin cell adenoma: Rare. Due to excessive secretion of FSH and LH, it can be asymptomatic in the early stage, but in the late stage, there is hypogonadism, amenorrhea, infertility, impotence, testicular atrophy and decrease in sperm count. Visual dysfunction may occur when the tumor grows. Non-secretory adenoma: Mostly seen in middle-aged and old men and post-menopausal women, it used to be called pituitary pheochromocytic adenoma, which lacks plasma hormone level and has no significant clinical symptoms. When the adenoma grows and compresses the optic chiasm* and pituitary tissue, headache, visual dysfunction and hypopituitarism may occur, and a large adenoma with mildly elevated plasma PRL.