Pituitary tumors are a group of tumors that occur from the anterior and posterior pituitary lobes and the epithelial remnants of the craniopharyngeal canal. Clinically significant symptoms account for approximately 10% of intracranial tumors. They are slightly more common in men than in women and usually occur in young adulthood, often affecting the patient’s growth and development, reproductive function, learning and work ability. Clinical manifestations include abnormal hormone secretion syndromes, tumor compression of peripituitary tissues, pituitary stroke and other manifestations of anterior pituitary hypoplasia. The majority of tumors in this group are adenomas from the anterior lobe, and those from the posterior lobe are rare. According to incomplete statistics, PRL tumors are most common in 50-55% of cases, followed by GH tumors in 20-23%, ACTH tumors in 5-8%, and TSH and LH/FSH tumors in less common cases. Non-functioning pituitary adenomas account for 20-25% of cases.
The causes of pituitary tumors are roughly hypothalamic malfunction and pituitary cells’ own defects. Dr. Sun explains the following: 1. Hypothalamic regulatory malfunction: Hypothalamic peptide hormones promote proliferation of pituitary cells, such as transplantation into GHRH gene, which can trigger proliferation of GH cells in rats, and then develop into real pituitary tumors.
The lack of inhibitory factors can also play a role in promoting tumorigenesis, such as ACTH adenoma can occur in patients with primary adrenocortical hypofunction.
Pituitary adenomas arise from a mutated cell with subsequent monoclonal expansion or cell replication due to its own mutation.
Involvement of external promoters or lack of inhibitors: ① Defects in DA (dopamine) receptor gene expression.
② The role of oncogenes and oncogenes: oncogenes are actually a class of genes involved in the regulation of normal cell growth. Some oncogene products are growth factors and their receptors, while others are involved in the process of growth signaling in the cell, and abnormalities in their expression can all lead to abnormal cell proliferation.