Synonyms in a broader sense
Pituitary adenoma, tumor of the pituitary gland
Definition
A pituitary tumor is a mostly benign new formation of hormone-forming cells of the pituitary gland (hypophysis). The pituitary gland is a gland about the size of a cherry stone, located in the middle of the skull at the base of the skull, approximately at the level of the nose, and is divided into a front and a rear lobe. As a hormone-forming gland that produces very different types of messenger substances (hormones), the pituitary gland is the important interface between the brain and the hormone system. The most common pituitary tumor originates from the anterior lobe of the pituitary gland and is called pituitary adenoma. In the case of a pituitary tumor, a distinction is made between the hormonally inactive and the hormonally active ones, whereby the latter are still classified according to the type of hormone (pituitary tumor).
Frequency
Although the pituitary gland does not consist of brain tissue, the pituitary tumor is counted among the brain tumors and accounts for 10 to 15% of all brain tumors. About 3 to 4 people per 100,000 fall ill every year, with no preference given to a particular age or gender.
Causes
So far, no causes for the development of a pituitary tumor are known. However, there is a rare hereditary disease, the so-called Multiple Endocrine Neoplasia (MEN-1), in which there is an increased tendency to develop a pituitary tumor, which is then usually accompanied by an overactive parathyroid (adrenal gland) and tumors of the pancreas. A pituitary tumor usually originates from a single degenerated cell.
Since the cells produce different hormones, several types of tumors can be distinguished, which, depending on the hormone produced, also cause different symptoms. Some symptoms can be attributed to the location of the pituitary gland and to the fact that the tumor displaces brain tissue as it grows. The pituitary gland lies directly under the crossing of the optic nerves.
When the pituitary tumor grows and consequently presses on the nerves, characteristic visual field deficits occur that affect the external visual field, which is why it is also called “blinker blindness” (bitemporal hemianopsia). A hormone-inactive pituitary tumor does not cause symptoms until late and is therefore usually only discovered when it is already relatively large. This tumor can also produce hormones, but these are not effective.
Symptoms occur because the pituitary tumor displaces healthy tissue, resulting in a deficiency of biologically active pituitary hormones. The hormone-active pituitary tumors are characterized by the fact that they produce uncontrolled large amounts of hormones. With almost 40%, prolactinoma is the most common pituitary tumor.
If too much of the body’s own hormone prolactin is produced, women may stop having periods and produce milk. In men, an enlargement of the breast can often be observed, which can also be associated with milk production. The second most common type of tumor is a growth hormone-producing pituitary tumor.
In this case the growth hormone (HG; also: somatotropic hormone, STH) is produced in increased quantities, which regulates the growth in length and also the blood sugar level. Overproduction in childhood can therefore lead to so-called giant growth. This is no longer possible in adults, where the end parts of the body such as hands and feet, chin, nose or eyebrow bulges (acromegaly) grow.
Often the first thing that affected adults complain about is that rings, hats or (hand) shoes no longer fit. Up to 20% of patients also develop diabetes mellitus. ACTH-producing pituitary tumors occur even less frequently.
This causes increased stimulation of the adrenal cortex, which then releases an increased amount of various hormones, with cortisol playing a central role here. This hormone influences the blood sugar level, the water balance of the body and the immune system. An excess leads to increased blood sugar, reduced bone density (osteoporosis), trunk obesity, bull neck and a full moon face.
This disease is called Cushing’s disease. A common symptom of large pituitary tumors is impaired vision with loss of visual field. Lateral and above the pituitary gland run the large optic nerves, which originate in each eye and are connected directly in the area of the pituitary gland (chiasma opticum).
The growth in size of a pituitary tumor can lead to a compression of the inner pathways of the optic nerve. As a result, the patient suffers from lateral visual field loss with reduced visual acuity (‘blinkers’). The specialist also refers to this as bitemporal hemianopsia.Another common symptom of a pituitary tumor is headache.
These occur mainly with larger tumors. Due to the central location of the pituitary gland in the Turk’s saddle of the skull (sella turcica), it is surrounded by numerous vessels and nerves. If the size of the tumor increases significantly, both the surrounding nerves and the sensitive nerves of the meninges in the area of the Turkish Saddle can be irritated.
As a result, the patient may experience headaches, some of which are diffuse and spread over the entire head. At the beginning, patients often report a sudden onset of headache in the forehead and eye area, which then spreads increasingly over the entire head. For more detailed information on this topic, we recommend that you visit our website: These symptoms indicate a pituitary tumor!
The signs of a pituitary tumor are manifold. Due to its displacing growth in the bony limited Turk’s saddle (Sella turcica) surrounding structures are compressed or irritated. These include the optic nerve, which runs directly above the pituitary gland.
In the case of particularly large tumors, visual field failures can occur. Typically, the visual field is restricted on the outside (‘blinkers’). In addition, the growth in size can also irritate sensitive nerves in the area of the meninges, causing the patient to develop headaches, some of which are very severe.
Furthermore, depending on the hormone production of the tumor, further symptoms may occur. While the tumor usually produces an excess of one hormone, the other cells of the pituitary gland are compressed and their function is disturbed. For this reason, hormone deficiency symptoms usually occur.
In the most common prolactinoma, which develops from prolactin-producing cells, the woman’s ovulation and menstrual periods fail to occur due to the increased prolactin levels. In men, disorders of potency and libido (sexual desire) can also occur. At the same time, very large prolactinomas result in a reduced production of growth hormone.
While this leads to growth disorders in children, osteoporosis can occur in adults. As the disease progresses, there is also a reduced production of sex, thyroid and steroid hormones, each with its own specific symptoms. Further information on this topic can be found at These symptoms indicate a pituitary tumor!
