Overview
Pituitary tumors are a group of tumors arising from the anterior and posterior pituitary lobes and the remnant cells of the craniopharyngeal duct epithelium. Clinically significant symptoms account for approximately 10% of intracranial tumors. They are slightly more common in males than females and usually occur in young adulthood, often affecting the patient’s growth, reproductive function, learning and work ability. Clinical manifestations include abnormal hormone secretion syndrome, tumor compression of peripituitary tissues, pituitary stroke and other manifestations of anterior pituitary hypofunction.
Etiology
Pituitary adenomas are a group of tumors that arise from the anterior and posterior pituitary lobes and the remnant cells of the craniopharyngeal duct epithelium. There are two theories for the pathogenesis of pituitary adenoma, one is the pituitary cell self-deficiency theory, and the other is the hypothalamic dysregulation theory.
1. Hypothalamic dysregulation.
(1) Hypothalamic peptide hormones promote the proliferation of pituitary cells, such as transplantation of GHRH gene, which can trigger the proliferation of GH cells in rats, and then develop into real pituitary tumors.
(2) 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.
2. Pituitary cell self-deficiency theory.
(1) Pituitary adenoma originates from a mutated cell with subsequent monoclonal expansion or cell replication caused by its own mutation.
(2) Involvement of external promoters or lack of inhibitors.
(1) Defective expression of DA (dopamine) receptor genes.
(2) 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 intracellular transmission of growth signals, and abnormalities in their expression can lead to abnormal cell proliferation.
Clinical manifestations
1.Abnormal hormone secretion syndrome.
Hormone overproduction syndrome, such as growth hormone overproduction causing acromegaly; hormone underproduction syndrome. When the non-functional tumor enlarges and the normal pituitary tissue is damaged, amenorrhea occurs due to reduced gonadotropin secretion. Infertility or impotence often occurs earliest and is more common.
2.Tumor compression of peripituitary tissue syndrome.
(1) Nerve fiber irritation with persistent headache.
(2) Patients with optic nerve, optic cross and optic nerve bundle compression present with visual acuity loss, visual field defects and fundus changes; other compression syndromes.
(3) Pituitary stroke.
(4) Others.
Prevention
1.Postoperative complications.
Pituitary tumor surgery can affect the posterior pituitary gland, which can easily cause insufficient secretion of posterior pituitary hormone after surgery, which can lead to increased urine output and even urinary collapse. Other complications, such as hypothalamic reaction, optic nerve damage, cerebrospinal fluid leakage, etc.
2. Review.
Some aggressive pituitary tumors are very prone to recurrence. Patients need to be reviewed three days, one month, three months, six months and one year after surgery to observe the dynamic changes in the operated area and to evaluate the efficacy of the surgery.
3. Radiotherapy after surgery.
Only some invasive pituitary tumors with residual or recurrence after surgery should be treated with radiotherapy or gamma knife.