A pituitary tumor is a predominantly benign growth of the pituitary gland that accounts for about 30 to 40 percent of brain tumors. Pituitary tumors are usually easily treatable due to modern microsurgical procedural techniques.
What is a pituitary tumor?
Schematic diagram showing the location of a brain tumor in the brain. Click to enlarge. A pituitary tumor is a pathological, usually benign (benign) neoplasm of the pituitary gland. A distinction is made between the more frequently diagnosed pituitary adenomas, which account for a total of 15 percent of brain tumors and arise from cell tissue of the anterior lobe of the pituitary gland (adenohypophysis), and the extremely rare tumors of the posterior lobe of the pituitary gland (e.g. granular cell tumors of the neurohypophysis). The pituitary gland is a hormonal gland about the size of a bean that acts as an interface between the brain and the endocrine system and is significantly involved in the hormonal regulatory system. Since a pituitary tumor arises from tissue cells of the pituitary gland, it can take over its hormone-producing properties. Therefore, an additional differentiation is made between hormone-inactive and hormone-active pituitary tumors. The predominantly occurring hormone-active pituitary tumors produce hormones and impair the hormonal regulatory system of the pituitary gland as a result of an excess of hormones. The most common pituitary tumor is prolactinoma (about 40 percent of pituitary tumors), which is a hormone-active tumor that produces prolactin.
Causes
The causes of a pituitary tumor are not clearly understood to date. It is suspected that a pituitary tumor arises from a single abnormal pituitary tissue cell that divides, multiplies, and forms a tumor, with no specific cells at particular risk for degeneration. The triggers for this degeneration process are also unknown and a correlation between environmental factors acting on the genome and the development of a tumor has not yet been demonstrated. In individual specific cases, genetic factors underlie a pituitary tumor. For example, multiple endocrine neoplasia (MEN-1 syndrome) carries an increased risk of pituitary tumors.
Typical symptoms and signs
- Visual disturbances
- Visual field defects
- Increase in pituitary hormones
Diagnosis and course
For the diagnosis of a pituitary tumor, diagnostic imaging techniques such as MRI, CT and X-ray are mainly used. MRI (magnetic resonance imaging) of the head, for example, can be used to locate a pituitary tumor and determine its size. A hormone determination of the blood provides information about the hormone activity and the type of pituitary tumor as part of a differential diagnosis. Thus, in the case of a prolactinoma, the prolactin value is elevated. An elevated value of growth hormones (above 5 ng/mm) indicates a growth hormone-producing pituitary tumor. In addition, a dexamethasone test can detect an ACTH-producing (adrenocorticotropic hormone) pituitary tumor. Since visual impairment is present in about 30 percent of cases of pituitary tumor, a close eye examination is indicated. In general, pituitary tumors are not lethal or life-threatening and the prognosis is favorable, although there is a high risk of recurrence. If left untreated, a pituitary tumor can affect adjacent organs (optic nerves, blood vessels) as it grows in size and leads to death in the majority of cases.
Complications
In most cases, a pituitary tumor can be treated and removed relatively well, resulting in no particular complications or discomfort for the patient. However, without treatment, the tumor in the brain can spread to other regions of the head and body and cause discomfort in those regions. Due to the pituitary tumor, visual disturbances occur in most cases. Vision may be reduced and the patient suffers from double vision or so-called veil vision. Furthermore, paralysis and failures in the different areas of the visual field can occur, so that the affected person can no longer move or control certain regions. These paralyses severely limit the patient’s daily life and result in a significant loss of quality of life. Treatment of the pituitary tumor is usually by radiation therapy, since surgical removal is not possible.There are no particular complications and the tumor can usually be removed relatively well. Furthermore, medication is used and the affected person must undergo repeated examinations in the following years. If the removal is successful, life expectancy is not affected.
When should one go to the doctor?
Depending on its size and location, a pituitary tumor can cause very different symptoms. A visit to the doctor is advisable as soon as signs of a hormone disorder appear, such as increasing fat deposits on the abdomen with simultaneous loss of muscle mass or unexplained enlargement of the hands and feet (acromegaly). Children should be presented to the pediatrician if the normal growth spurts fail to appear and their height lags significantly behind that of their peers. Menstrual irregularities and loss of sexual desire in women may indicate a tumor-related deficiency of female sex hormones. In this case, a visit to the gynecologist is recommended, who can rule out gynecological causes and, if necessary, arrange for further specialist clarification. In men, a pituitary tumor occasionally triggers potency disorders and a loss of libido; here, the urologist is a suitable first point of contact. Other warning signs of a tumor of the pituitary gland can be an increased sensation of cold, a slow pulse rate, low blood pressure, fatigue, loss of performance, noticeable pallor of the skin, headaches, visual disturbances and a tendency to hypoglycemia. Each of these signs can also be caused by other, far more harmless diseases – a visit to the family doctor is advisable if several symptoms occur at the same time, the complaints persist over a longer period of time or become increasingly worse. If the suspicion is confirmed, further examinations by an endocrinologist or by imaging procedures are advisable.
Treatment and therapy
The standard therapy for a pituitary tumor is microsurgery, although prolactinoma is an exception and is treated with medication. Because of the location of the pituitary gland, access to the tumor is through the nasal opening in most cases, and opening of the skull is required only for particularly large pituitary tumors. If the pituitary tumor proves to be inoperable or only partially removable, radiation therapy is also used. However, in some cases, due to the problematic location of the pituitary gland, radical removal of the residual tumor is not possible, so its development is monitored using imaging techniques (MRI) and, if necessary, a new surgical intervention is required. Prolactinoma, as a hormonally active pituitary tumor, is treated medicinally with dopamine agonists, which inhibit increased prolactin secretion and successively lead to minimization of the pituitary tumor. Microsurgical tumor removal is only considered in sufferers who cannot tolerate long-term drug therapy and when the tumor does not respond to the drug. The consequence of microsurgical and radical removal of the pituitary tumor is, in not infrequent cases, hypopituitarism, which results in hormone deficiency. This is compensated for with medication as part of substitution therapy.
Prevention
Since neither the exact causes nor the triggers for the assumed cell degeneration are known, it is not possible to prevent a pituitary tumor. In general, it is recommended to avoid carcinogenic substances such as chemicals, unnecessary radiation, and alcohol and nicotine. A healthy diet and exercise support the immune system and minimize the risk of disease in general and specifically with regard to pituitary tumors.
Follow-up
Following a pituitary tumor, there is often a hormone deficiency, triggered by the hypofunction of the pituitary gland. For this, the physician prescribes the appropriate medication. Patients should carefully follow the instructions for this substitution therapy in order to rule out any problems. In the post-treatment phase, it is important to avoid harmful stimulants such as alcohol and nicotine. Healthy foods and sufficient exercise help those affected to reduce the risk of disease and strengthen the immune system. With this improvement in health, patients feel armed against illness and relapse.Complementing the healthy diet, they can limit caffeine consumption and diet if they are overweight. Patients with a normal weight feel much better because their cardiovascular system is not overloaded. A doctor-recommended weight loss also has a positive effect on blood values and ensures greater fitness. That is why it is worthwhile to include sports and exercise in the aftercare program. The activities and subsequent relaxation phases also reduce everyday stress. This is another important point for health. With autogenic training and/or yoga, those affected also train their mindfulness and in this way increase their quality of life.
What you can do yourself
The pituitary tumor is a serious disease that patients should by no means treat or ignore on their own. It is very important that the therapy is determined in consultation with the treating physician and carried out consistently. Active participation by the patient is possible. The patient can follow the therapy plan consistently, attend control examinations, and actively report changes, abnormalities, or possible new symptoms to the physician. Parallel to the tumor therapy, the patient can try to achieve an immune system that is as stable as possible and a good general physical condition. A first step towards this is to abstain from harmful substances such as nicotine and alcohol. Caffeine consumption can also be reduced to one or two cups a day. If the patient is overweight, he should try to reach a normal weight. This will relieve the strain on his cardiovascular system and put him in a fitter, healthier state. Weight loss can usually be achieved quickly via a change in diet, and blood values and the overall physical condition also improve. An appropriate sports or exercise program supports these measures. In this way, the patient himself can ensure that he has a healthier body to better cope with the strenuous stresses of the therapies. Stress and pressure in everyday life can be avoided or reduced in many cases. Autogenic training or yoga can contribute to relaxation.
