Pituitary Adenomas

There are two main systems that control the functions of the body. The first of these is the “nervous system”, which takes its source from the brain and spinal cord and distributes it throughout the body, and the second is the “hormonal system” or “endocrine system”, which manages the body’s functions by watching in the blood that constantly circulates throughout the body. These two systems work in connection with each other.

Hormones are chemical substances secreted by cell communities or secretory glands in the body. There are two glands belonging to the endocrine system in the brain. The first is the pituitary gland, the second is the pineal gland. Tumors involving the pineal gland are very rare. The pituitary gland, located at the base of the skull and under the brain, is a vital organ that is the control center that ensures the secretion of many hormones in our body and the body’s water balance.

Tumors involving the pituitary gland are detected at a rate of 5-10% among all brain tumors. Dec. Pituitary adenomas are mostly benign tumors. Pituitary gland tumors give symptoms in the body in two ways. The first is the mass effect, in which tumors that grow too much give symptoms by compressing the structures around them. In this case, the visual nerve, especially near the gland, is affected and the patient has decreased vision or vision loss. If the tumor grows more, loss of function of the nerves that make eye movements may also occur. When the pituitary gland reaches such a large size, there may also be a deficiency in various hormones secreted from the pituitary gland, as the normal pituitary tissue will lose its function. The tumor shows its second effect by overgrowing the gland or by excessive secretion of some hormones without enlarging it. If the pituitary gland has grown so much that it does not exceed 1 cm, these tumors are called microadenomas, and if they are larger than 1 cm, they are called macroadenomas. Adenomas that do not secrete hormones usually grow slowly and can remain for years without symptoms. Those who secrete hormones, on the other hand, give early symptoms due to the effects of hormones in the body.

The pituitary gland consists of two parts; the anterior pituitary and the posterior pituitary. Pituitary gland tumors are mainly tumors belonging to the anterior pituitary gland. Tumors arising from this cause symptoms either due to excessive hormone secretion or due to excessive growth, pressure and spread to the surrounding tissues.

The hormones secreted from the anterior pituitary and their functions are as follows:

Prolactin hormone: allows the secretion of milk from the breast.
Growth hormone: controls the metabolism of carbohydrates, fats and proteins in the body. It ensures the balanced growth of the body, especially during adolescence.
Adrenocorticotrophic hormone: regulates the secretion of cortisol, which is of vital importance from the adrenal glands.
Thyroid-stimulating hormone: provides the secretion of thyroid hormones from the thyroid gland.
Gonadotrophic hormones: they control the functions of the reproductive organs.

When the body secretes more hormones than it needs, it causes an increase in the functions of that hormone or hormones in the body. In this case, for example; if excessive prolactin is secreted, milk comes from the breast even though the patient is not pregnant. If excessive growth hormone is secreted in an adult, shoes may start to get tight on the feet as a result of excessive growth of the body.

The posterior pituitary secretes antidiuretic hormone, which regulates the urine output from the body, and a hormone called oxytocin, which allows uterine contraction at birth. Tumors belonging to the posterior pituitary are almost never seen.

Frequency

Pituitary adenomas are 3 among all tumors located in the head, after those originating from the brain itself and its membrane. it takes place next. So it is a relatively common tumor. The reasons for their appearance are not fully understood. They are rarely seen together with hereditary diseases with genetic transmission.

Complaints and Findings

Pituitary adenomas cause complaints either according to the type of hormone they secrete, or because the tumor grows too much and puts pressure on the surrounding tissues. A type of hormone with various effects is secreted from the pituitary gland, and such adenomas give signs according to the effect of an excess of secreted hormone. For example, if the hormone that causes milk formation (prolactin) is secreted too much, the arrival of milk from the breast in women gives symptoms such as menstrual disorders. In men, conditions such as a decrease in sexual power, a decrease in beards, and breast growth may occur. If growth hormone is secreted excessively, symptoms such as growth on the hands, feet and tongue, excessive snoring, breathing problems, diabetes and high blood pressure occur. If there is an excessive release of cortisol, severe symptoms such as accumulation of excess fat in the body, rashes on the skin, treatment-resistant diabetes and the appearance of high blood pressure are observed. In addition, in some patients, headaches may occur that spread to the eyes and neck because the pituitary tumor grows and stretches the brain membrane. Oct. If the tumor presses on the optic nerve, visual disturbances may occur. The most typical visual impairment is the patient’s inability to see both sides clearly. In extremely large tumors, this condition can progress to blindness. Pituitary adenomas that do not secrete hormones, on the other hand, can cause all pituitary hormones to decrease because they crush the normal pituitary tissue. In this case, signs of hormone deficiency such as weakness, fatigue, low blood pressure, dry skin, decreased sexual power may occur in patients. Rarely, pituitary adenoma can bleed and sometimes leads to sudden vision loss. This condition requires urgent surgical treatment.

Types of Pituitary Adenoma

Pituitary adenomas are two groups as hormone-secreting and non-secreting adenomas. Those who secrete hormones are classified and named according to the type of hormone they secrete.

Diagnosis

Blood hormone tests and visual examination are performed primarily in patients with pituitary adenoma findings. Pituitary Magnetic Resonance Imaging examination is required for a definitive diagnosis. In Cushing’s Disease, it may be necessary to take a blood sample from the pituitary gland next to the brain angiography very rarely.

Treatment

Endocrinology and Neurosurgery departments usually decide on the treatment planning of patients diagnosed with pituitary adenoma together. There are three main types of treatment options, taking into account the patient’s findings, the size of the adenoma and the hormone status:

1- Drug Therapy: It is the first option in the treatment of prolactinomas in particular and is an auxiliary method in other adenomas. The majority of prolactinomas respond well to this treatment. Some growth hormone-secreting pituitary adenomas can also be controlled with medication. It is possible to control excessive hormone secretion with drug therapy. But when the drug is discontinued, hormone secretion in most patients increases back to its former level. The patient may need to use the drug all his life.

2- Surgical Treatment: It is the first and most effective treatment option for all adenomas with pressure signs except prolactinomas. Two main methods are used:

Intervention through the nose: It can be performed with the help of a microscope or endoscopically. These are the most preferred methods today.
Open surgery: It can be preferred for adenomas that grow and spread excessively into the brain. It is used less and less nowadays.

The goals of surgical treatment are as follows:

To remove the pressure that the tumor exerts on the surrounding tissues, for example, on the visual nerves,
To ensure a better response to treatment with medication by reducing the tumor mass.

3- Radiation therapy: It is used for tumors that cannot be completely removed by surgery or that recur despite all treatments. Today, focused radiation therapy methods called Gamma and Cyber Knife are most preferred.

Treatment Results

When all the treatment options mentioned above are used, more than 90% of pituitary adenomas respond well to treatments.

Currently, surgical treatment by entering through the nose is preferred in the surgical treatment of pituitary tumors. The rates of complications that the patient may encounter depending on the surgery are given below: