Pituitary tumors are a group of tumors that occur from the epithelial remnants of the craniopharyngeal canal in the anterior and posterior pituitary lobes. The majority of tumors in this group are anterior pituitary adenomas, and those from the posterior pituitary are rare.
As the level of pituitary tumor detection continues to improve, the incidence of pituitary tumors has a tendency to increase year by year.
At present, there is a lack of epidemiological investigation data of pituitary tumors in China. According to the American epidemiological survey, the incidence of pituitary adenoma is 10-15/100,000. The incidence of pituitary adenoma during autopsy of normal deceased patients varies, ranging from 9% to 65%. In a group of foreign studies, a random sample of 100 normal people was selected for MRI of the pituitary gland, and the detection rate of pituitary adenomas was 16%, indicating that the incidence of pituitary adenomas is very high, but most patients do not show clinical symptoms.
Pituitary tumors occur mostly in young adults and often affect the patient’s growth and development, reproductive function, learning and working ability. The clinical manifestations of pituitary tumors vary widely, and the departments where patients are first seen can be relatively fragmented.
In some primary and specialized hospitals, due to the lack of centers for comprehensive pituitary adenoma treatment, patients are often transferred to multiple departments and are not properly diagnosed and treated for a long time, thus delaying their illness and causing unnecessary mental and material stress to patients.
There are two theories of pituitary adenoma pathogenesis, one is the theory of pituitary cells’ own defects and the other is the theory of hypothalamic dysregulation.
(1) Hypothalamic deregulation: (1) Hypothalamic peptide hormones promote the proliferation of pituitary cells, such as transplantation into the GHRH gene, which can trigger the proliferation of GH cells in rats and then develop into real pituitary tumors.
(2) Lack of inhibitory factors can also contribute to tumorigenesis, e.g., ACTH adenoma can occur in patients with primary adrenocortical hypofunction.
(3) Other factors, such as interleukin-6, can be highly expressed in pituitary tumors and have a pro-growth effect in maintaining the tumor. All of these may be contributing factors to pituitary adenoma.
2. Pituitary cell self-defect theory: It is believed that the genetic mutation of pituitary adenoma cells is the main initiating factor.
(1) Schulte and other studies found that most pituitary adenomas are monoclonal, pituitary adenoma from a mutated cell, and subsequently occur monoclonal expansion or self-mutation resulting in cell replication.
(2) Involvement of external promoters or lack of suppressors.