Pituitary Tumor (Adenomas): What is it, Causes, Symptoms and Treatment

Each organ that makes up the hormone system undertakes important tasks for our body.

Each organ that makes up the hormone system undertakes important tasks for our body. For this reason, serious clinical complaints may be encountered in various diseases affecting the endocrine system. In this sense, one of the hormonal system diseases that can be seen in society and cause different clinical pictures is tumor formations called adenomas that develop in the pituitary gland.

What is the Pituitary Gland?

Pituitary gland; It is a hormone gland approximately the size of a hazelnut, located inside the skull, in the lower part of the brain and adjacent to the nasal cavity. The pituitary gland is located within the protective bone structure called Sella Turcica (Turkish Saddle). The transmissions coming from the upper centers of the brain are first transmitted to the Hypothalamus, and from there to the pituitary gland via the pituitary stalk, where the hormones necessary for the body are secreted. In other words, the pituitary gland constitutes the main control point of the hormone system. Hormones of the pituitary gland function indirectly in regulating the functioning of internal organs by controlling other hormone glands.

The pituitary gland is examined in three parts: It is divided into anterior, posterior and middle pituitary. Basically, hormone production occurs in the anterior pituitary. Only melanocyte-stimulating hormone is produced in the middle pituitary. The posterior pituitary is the part that communicates with the Hypothalamus and two different hormones are produced here.

1. The anterior pituitary gland is basically responsible for the production of six different hormones and is the part directly related to the endocrine system. Accordingly, the following hormones are produced from the anterior pituitary gland:

• Growth hormone (GH): Affects the entire body and ensures the maturation and growth of organs during the growth and development period; It helps maintain cell functions throughout the body during adulthood.
• Adrenocorticotropin hormone (ACTH): It is responsible for regulating the production of vital hormones such as cortisol, aldosterone and androgen derivatives, which are secreted from the adrenal glands.
• Thyroid stimulating hormone (TSH): It regulates the production of hormones of the thyroid gland, which is another group of hormones that are vital for the body.
• Follicular stimulating hormone (FSH): FSH, which is responsible for the development of reproductive cells in the ovaries in women; It also plays a role in regulating sperm production in men. It also regulates the production of sex hormones such as estrogen, progesterone and testosterone.
• Luteinizing hormone (LH): While it ensures that maturing egg cells in women are thrown into the reproductive tract; It is responsible for sperm production and maturation in men. Apart from this, it plays a role in regulating the production of sex hormones together with FSH.
• Prolactin: It is the main hormone that ensures breast milk production in women after birth. Apart from this, it is known to have various psychological effects by regulating the reproductive system.

2. The posterior pituitary gland is responsible for the production of two different hormones; It has a tissue structure that directly connects with the hypothalamus:

• Antidiuretic hormone (ADH): It regulates the amount of urine and the availability of water in the body by triggering water retention from the kidneys.
• Oxytocin: It is the hormone that initiates labor contractions in women and stops birth bleeding by shrinking the uterus after birth. Apart from this, it functions to force breast milk out of the breast tissue.

What is a Pituitary Tumor?

The formation of a mass as a result of uncontrolled division and proliferation of the cells that make up the tissue of the pituitary gland for various reasons is called pituitary adenoma. Pituitary adenomas; Although they are benign tumors in terms of their functions and structure; Depending on their size and function, they can negatively affect health by causing various clinical symptoms. Quite rarely, pituitary tumors can become cancerous. Again, pituitary adenomas observed in the clinic usually arise from the anterior pituitary.

Clinical symptoms of pituitary adenomas vary depending on the pituitary cell from which they originate, whether it produces hormones, and the tumor size they reach. Accordingly, adenomas with a diameter of less than 1 cm are called microadenomas; Adenomas larger than 1 cm are called macroadenomas. Although microadenomas often do not cause any significant problems to the surrounding tissues; Macroadenomas may cause problems in the anatomical structures adjacent to the pituitary gland and the pituitary gland itself through compression.

Apart from this, adenomas can show functional properties and produce certain hormones in higher than normal amounts, uncontrolled, depending on the cell they originate from. Accordingly, adenomas that can produce growth hormone, ACTH, TSH, prolactin, FSH or LH hormones may develop. Tumor structures located in or around the pituitary gland and originating from different tissue types belonging to the embryological period in the womb can also develop (such as craniopharyngioma, teratoma, gangliocytoma).

In the light of this information, the majority of pituitary adenomas encountered in the clinic are of the microadenoma type and are prone to producing prolactin; The majority of tumors observed as macroadenomas are non-functional and develop a clinical picture by compressing the surrounding tissues without producing any hormones.

What Causes Pituitary Tumor?

In the current clinical approach, it is not known exactly why pituitary adenomas develop. However, as a result of research, it has been determined that the probability of developing pituitary adenoma is high in patients with some risk factors. These factors are genetically based and can be summarized as follows:

• Multiple endocrine neoplasm syndrome type 1 (MEN-1) patients
• McCune–Albright syndrome patients
• Patients with Carney complex
• People who have a similar family history of pituitary adenoma

What are the Symptoms of Pituitary Tumor?

Symptoms that develop due to pituitary tumors may be caused by the pressure on the surrounding tissues depending on the size of the tumor; It may also develop due to hormone deficiency, causing deficiency in the functional part of the pituitary. If the tumor is a functional mass with hormone production, symptoms related to excess hormone production may be added to the table. In this regard, the question “What are the symptoms that occur with pituitary tumor?” in pituitary tumors, which can cause a wide variety of clinical pictures. It would be more logical to ask the question.

In this context, in cases where pituitary adenomas reach large sizes, the following symptoms may be observed due to pressure on the surrounding tissues:

• Vision loss or decreased visual field (especially loss in the areas of the outer quadrants of the eye)
• Headache
• Nausea – vomiting
• Weakness, fatigue, menstrual irregularities, sexual dysfunction, increased urine output, weight gain due to pressure on the pituitary gland

Apart from these, if the adenoma is functional, the following symptoms may be added to the table depending on the hormone whose amount increases:

• In excess of prolactin; menstrual irregularities or complete disappearance of menstruation, milk secretion from breast tissue, sexual dysfunction in men, decrease in the amount of sperm, development in breast tissue
• In excess of growth hormone; excessive elongation during growth period; In adulthood, elongation of the extremities of body parts such as the chin, tip of the nose, hands and feet, sweating, high blood sugar, joint and heart problems
• In ACTH excess; Fat accumulation in abnormal areas of the body, muscle weakness, high blood pressure and blood sugar, oily skin and acne development, stretch marks, psychological problems.
• In excess TSH; weight loss, palpitations, intestinal problems, sweating, restlessness and irritability
• In FSH – LH excess; menstrual irregularities, sexual function problems, infertility

How is Pituitary Tumor Diagnosed?

Since pituitary tumors can cause very different clinical pictures, the detailed disease history taken by a specialist physician and the data obtained after a detailed physical examination are combined with information obtained from additional imaging and laboratory tests. In the light of all these examinations, the presence and characteristics of the adenoma are determined and a diagnosis is made.

The tests used include hormone tests in blood and urine, imaging of the brain region using methods such as computerized tomography and magnetic resonance (MRI), and visual field tests.

How is Pituitary Tumor Treated?

The treatment method for pituitary tumor is determined primarily depending on the patient’s clinical findings and the level of health impact. In this context, treatment decisions may not be taken when microadenoma tumors do not cause any functional or anatomical problems. However, for larger and functional tumors, different treatment methods may be required. Accordingly, the following methods are used in the treatment of pituitary tumor:

• Follow-up: Close follow-up may be recommended for tumors that are small in size, non-functional and do not cause any clinical symptoms. In this case, patients are examined intermittently to see if there is any change in the behavior and size of the tumor.
• Surgery: The adenoma may need to be removed surgically, especially in tumors that cause pressure symptoms. Two different methods can be applied here. In the first method, called the endoscopic transnasal transsphenoidal approach, the surgery involves removing the mass with a closed technique with the help of endoscopes sent into the nose. The second method is the transcranial approach; It refers to the removal of the mass by open brain surgery method.
• Radiotherapy: After surgical treatment or in patient groups where surgery cannot be performed, it may be aimed to remove the mass with radiotherapy using concentrated X-rays. External radiotherapy or stereotactic radiosurgery methods can be used.
• Drug treatment: Various drug treatments can be used to relieve symptoms that develop due to increases or decreases in the amounts of pituitary hormones in the blood.