Pituitary tumor
Synonyms in a broader sense
Pituitary adenoma, tumor of the pituitary gland
English: pituitary tumor
definition
A Pituitary tumor is a mostly benign neoplasm of hormone-producing cells of the Pituitary gland (Pituitary gland). The pituitary gland is about the size of a cherry stone and is located in the middle of the skull in the base of the skull, approximately at the level of the nose, and is divided into an anterior and a posterior lobe. As a hormone-forming gland that produces very different types of messenger substances (hormones), the pituitary gland represents the important interface between the brain and the endocrine system. The most common pituitary tumor originates from the anterior pituitary gland and is known as pituitary adenoma. In the case of a pituitary tumor, a distinction is made between hormonally inactive and hormonally active ones, whereby the latter are classified according to the type of hormone (pituitary tumor).
frequency
Although the Pituitary gland does not consist of brain tissue, the pituitary tumor becomes the Brain tumor counted and makes up 10 to 15% of all Brain tumors out. Every year around 3 to 4 people per 100,000 fall ill, whereby neither a certain age nor gender is preferred.
causes
So far there are no causes for a Pituitary tumor known. However, there is a rare hereditary disease, the so-called Multiple endocrine neoplasia (MEN-1), who have an increased tendency to develop a pituitary tumor, which is most often caused by an overactive parathyroid gland (Adrenal gland) and tumors of the pancreas is accompanied.
Symptoms
A Pituitary tumor usually assumes a single degenerate 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 traced back to the location of the pituitary gland and the fact that the tumor displaces brain tissue as it grows. The Pituitary gland is just below the junction of the optic nerves. When the pituitary tumor grows and as a result to the annoy expresses, characteristic Visual field lossthat affect the external field of vision, which is why one is here also from "Blinker blindness" speaks (bitemporal hemianopia).
A hormonally inactive pituitary tumor only causes symptoms 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 when the pituitary tumor displaces healthy tissue, resulting in a deficiency of biologically active pituitary hormones.
You can find further information under our topic: Brain tumor signs.
The hormone-active pituitary tumors are characterized by the fact that they produce large amounts of hormones in an uncontrolled manner.
At almost 40%, the prolactinoma is the most common pituitary tumor. If too much of the endogenous hormone prolactin is produced, women may miss their periods and produce milk; men often have an enlarged breast, which is also accompanied by milk production can be connected.
The second most common is a growth hormone-producing pituitary tumor. Here, the growth hormone (HG; also: somatotropic hormone, STH) is increasingly formed, which regulates the growth in length and also the blood sugar level. In the case of overproduction in childhood, so-called giant growth can arise. In adults, this is no longer possible, as the extremities of the body such as hands and feet, chin, nose or eyebrow bulges grow here (acromegaly). Affected adults often complain first that rings, hats or (hand) shoes no longer fit. Up to 20% of patients also develop diabetes mellitus (Diabetes).
An ACTH-producing pituitary tumor occurs even more rarely. This causes an increased stimulation of the adrenal cortex, which then releases an increasing number of different hormones, with cortisol playing a central role here. This hormone affects blood sugar levels, the body's water balance and the immune system. An excess leads to increased blood sugar, decreased bone density (osteoporosis), trunk obesity, bull neck and a full moon face. This disease is called Cushing's disease.
Read more about the topic here: Cushing's disease.
Visual disturbance as a symptom
A common symptom of large pituitary tumors is visual disturbance with impaired visual field. The large optic nerves run to the side and above the pituitary gland, which arise at the respective eye and are connected directly in the area of the pituitary gland (optic chiasm).
The growth in size of a pituitary tumor can compress the inner tracts of the optic nerve. As a result, the patient suffers from lateral visual field defects with reduced visual acuity ('blinkers'). The expert also speaks of a bitemporal hemianopia.
Headache as a symptom
Another common symptom of a pituitary tumor is a headache. These occur mainly with larger tumors.
Due to the central position of the pituitary gland in the Turkish saddle of the skull (sella turcica), it is surrounded by numerous vessels and nerves. With a strong increase in size, 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 diffuse headaches that are distributed over the entire head.
At the beginning, the patients often report a sudden onset of headache in the forehead and eyes, which in the further course spreads increasingly over the whole head.
For more detailed information on this topic, we recommend our page on: These symptoms indicate a pituitary tumor!
What are the signs?
The signs of a pituitary tumor are many. Due to its displacement growth in the bony Turkish saddle (Sella turcica), surrounding structures are compressed or irritated. This includes the optic nerve, which runs directly above the pituitary gland.
In the case of particularly large tumors, visual field defects can occur. Typically, the field of vision is restricted on the outside ('blinkers'). In addition, the increase in size can also stimulate sensitive nerves in the area of the meninges, which can cause the patient to develop very severe headaches.
Further symptoms can also occur depending on the hormone production of the tumor. While the tumor usually produces an excess of one hormone, the other cells of the pituitary gland are compressed and their function is impaired. For this reason, hormone deficiency symptoms usually occur. The most common prolactinoma, which develops from cells that produce prolactin, causes women to fail to ovulate and menstruate because of the increased prolactin levels.
In men, potency and libido (sexual pleasure) disorders can also occur.
At the same time, very large prolactinomas lead to a reduced production of growth hormone. While this leads to stunted growth in children, osteoporosis can develop in adults. In the further course, there is also a reduced formation of sex, thyroid and steroid hormones, each with specific symptoms.
Further information on this topic can be found at: These symptoms indicate a pituitary tumor!
diagnosis
The hormonal changes mentioned above initially raise suspicion Pituitary tumorwhich must then be confirmed by imaging tests.
A X-ray image and the Computed Tomography (CT) only discover larger tumors, which is why the method of choice is the MRI of the brain in which the pituitary gland is made clearly visible by a contrast medium.
Furthermore, the examination of the hormone levels in the blood provide evidence of a pituitary tumor and also make it possible to differentiate between the different types.
MRI of the brain- what can you see on it?
Magnetic resonance imaging (MRI) is the method of choice for detecting a pituitary tumor (adenoma). It allows differentiation between micro- and macroadenomas based on the size of the tumor.
The MRI image of the brain usually shows a typical picture of a pituitary tumor. Due to the displacing growth, there is a mass in the area of the Turkish saddle (Sella turcica), which compresses the surrounding structures. As a result, for example, the optic nerves are lifted, the Turkish saddle widened and large vessels running in the vicinity (internal carotid artery) are pushed outwards. By administering a contrast agent, the tumor tissue can be easily distinguished from normal pituitary tissue. The tumor accumulates less contrast agent than the healthy tissue and thus appears darker.
therapy
Usually a Pituitary tumor surgically removed. There are two options: Because of its practical location, the tumor can in most cases be caused by the nose and the Sinuses removed. Only if the tumor is very large does the skullcap have to be opened and operated in this way.
Often the tumor cannot be completely removed, which is why it is important after surgery regular checks in the form of an MRI or of Hormone measurements perform.
This is an exception Prolactinoma that is pure in about 95% of patients medicinal can be treated well. Only if there is no response to the medication is an operation also resorted to with this type.
In rare cases, for example one Relapse (Relapse) or in the case of inoperable tumors, a radiotherapy be useful.
When do you need an operation?
The diagnosis of a pituitary tumor does not always have to be treated surgically. In the case of particularly small tumors (so-called microadenomas), for example, regular follow-up checks may be sufficient.
Surgical removal (resection) of the tumor is especially necessary when symptoms occur.
The urgency of the operation depends on the symptoms caused by the tumor. In the case of visual field defects or severe hormone deficiencies, surgical removal of the tumor is usually the only way to cure it.
In rare cases, complete resection is not possible. As a result, regular check-ups or a new operation are required. For inoperable tumors, radiation therapy is an alternative to surgical resection. Adenomas generally respond well to radiation therapy.
The most common prolactinoma is an exception. As a rule, this can also be treated with medication. The administration of dopamine agonists (e.g. bromocriptine) can slow down the growth of a prolactinoma and alleviate the symptoms.
How long does the operation take?
The duration of surgical removal of a pituitary tumor depends on the location of the tumor and the type of surgical procedure. While an endoscopic operation on the nose (transphenoidal) usually does not take longer than 1-2 hours, an operation with opening of the skull (transcranial) can take several hours.
Normally, no intensive treatment is required following surgical removal of the pituitary tumor.
How is the surgical route?
There are two different surgical procedures depending on the access route. The procedure of choice is the transphenoidal approach. Nowadays this is used in around 90% of cases. The operation is carried out through the nose with the help of an endoscope. The pituitary gland is accessed through the opening of the sphenoid sinus in the back of the nasal cavity.
In the case of very large tumors, the opening of the skull is necessary (transcranial access). Nowadays, this procedure is only used in around 10% of cases. After opening the skull, you get to the underside of the brain, where the pituitary gland is located.
forecast
Usually is a Pituitary tumor not immediately life threatening, because firstly it grows very slowly and secondly it is now easy to treat. However, side effects are often to be expected after an operation, which can be traced back to the fact that healthy pituitary gland tissue also had to be removed and this results in underactive hormones. However, this can be treated with medication.
Stay in Pituitary tumor If left untreated for a long time, it can be life-threatening, depending on its type and size.
