Pituitary adenoma
Pituitary adenoma is a benign tumor of glandular tissue. It is recognized as one of the most common tumors, since it is diagnosed in 15-20% of patients with neoplasms in the brain. This tumor is characterized by slow growth and benign course. Most often, a neoplasm in the pituitary gland is diagnosed in patients older than 30 years.
The content of the article:
Classification of pituitary adenoma
Causes of pituitary adenoma formation
Symptoms of pituitary adenoma
Diagnosis of pituitary adenoma
Treatment of pituitary adenoma
Prognosis of pituitary adenoma
Pituitary adenoma
The choice of tactics for the treatment of a tumor depends on its nature and size, the age of the patient, and the state of health. The leading methods of treatment of pituitary adenoma include neurosurgical (transnasal and transcranial adenomectomy), radiation, medication and combined.
Classification of pituitary adenoma
In neurology, an extensive classification of pituitary tumors has been developed. Depending on the size of the tumor , the following varieties are distinguished:
microadenoma (no more than 10 mm);
macroadenoma (10-30 mm);
mesoadenoma (10-20 mm);
giant adenoma (from 30 mm).
By the nature of staining, the adenoma can be chromophobic, basophilic and eosinophilic. According to the criterion of hormonal activity, active and inactive tumors are isolated.
According to the nature of the spread of the tumor in neurology , the following varieties are distinguished:
endosellar;
with suprasellar growth;
with infrasellar growth;
with parasellar propagation;
with retrosellar propagation.
Depending on the etiology, the neoplasm can be primary pituitary, secondary, and also caused by hypothalamic disorders. The classification of pituitary adenoma of the brain also provides for the isolation of several of its varieties, depending on the hormones produced in vivo and in vitro: STH-secreting (somatotropinoma), PRL-secreting (prolactinoma), ACTH-secreting (corticotropinoma), LH and FSH-secreting (gonadotropinoma), TSH-secreting (thyrotropinoma), alpha-secreting-subunit, mixed.
Causes of pituitary adenoma formation
The exact causes of pituitary adenoma formation have not yet been established in neurology. However, there are hypotheses that prove the appearance of a tumor due to infectious phenomena in the nervous system, traumatic brain injuries and the negative impact of various factors on the fetus. The most dangerous neuroinfections that can lead to the formation of a tumor include neurosyphilis, tuberculosis, brucellosis, encephalitis, polio, brain abscess, meningitis, cerebral malaria.
Neurology is currently conducting research aimed at establishing a link between the formation of pituitary adenoma and the use of oral contraceptives by women. Scientists are also investigating a hypothesis that proves that a tumor may appear due to increased hypothalamic stimulation of the pituitary gland. Such a mechanism of neoplasm occurrence is often observed in patients with primary hypogonadism or hypothyroidism.
Symptoms of pituitary adenoma
The clinical symptoms of pituitary adenoma usually become noticeable only when it reaches a significant size, which is why it begins to squeeze other brain structures. It is quite difficult to identify a tumor in the early stages of formation due to its small size and asymptomatic course of the disease.
Three groups of symptoms are characteristic of this formation: hypopituitarism, ophthalmic-neurological and endocrine-exchange syndromes.
Hypopituitarism
Hypopituitarism is characteristic of large tumors. It occurs due to the breakdown of pituitary tissue, provoked by the growth of a tumor. This pathological condition is characterized by sexual disorders, decreased libido, impotence, hypothyroidism and hypogonadism. Patients also have symptoms such as weakness, weight gain, dry skin, depression.
Ophthalmic neurological syndrome
The manifestations of this syndrome depend on the direction and prevalence of adenoma. The most characteristic symptoms of the ophthalmic neurological syndrome are changes in the field of vision, headache and oculomotor disorders. The headache occurs due to the pressure of the adenoma on the Turkish saddle. Usually, headache in patients does not depend on their body position, is not accompanied by nausea or vomiting, has a dull character.
Pain syndrome is localized in the temporal regions and behind the eye socket. In the case of accelerated tumor growth, a sudden increase in pain may occur, which cannot be eliminated even with the help of strong analgesics. If the adenoma begins to grow actively, it will sooner or later lead to compression of the optic nerves. As a result, the patient will not be able to avoid limiting the field of vision. If the adenoma develops for a long time, then the patient may even have atrophy of the optic nerves.
No less serious complications of the disease are also considered to be a decrease in visual acuity, a violation of oculomotor function. If the pituitary adenoma grows through the bottom of the Turkish saddle and begins to spread to the wedge-shaped or latticed sinuses, the patient may experience nasal congestion, the symptoms of which will be similar to signs of a nasal tumor or sinusitis. Active growth of pituitary adenoma upward can cause damage to the hypothalamus, which will lead to disorders of consciousness.
Endocrine exchange syndrome
Somatotropinoma — this type of pituitary adenoma in children is accompanied by signs of gigantism (height above two meters, violation of body proportions, elongation of limbs with a relatively small head). In adult patients, the disease can manifest itself as acromegaly — an increase in individual parts of the body. The signs of this tumor also include obesity, thyroid enlargement, diabetes mellitus, hirsutism, and the formation of warts on the skin.
Prolactinoma — this type of pituitary adenoma activates the secretion of prolactin. In women, the disease manifests itself with signs such as amenorrhea, menstrual cycle problems, galactorrhea and even infertility. In rare cases, women with prolactinoma complain of acne, seborrhea, hypertrichosis. In men, the most characteristic manifestations of the tumor are ophthalmic and neurological symptoms, as well as impotence, gynecomastia and decreased libido.
Corticotropinoma — this tumor always accompanies Itsenko-Cushing’s disease. It is characterized by signs of hyperkerticism and pronounced skin pigmentation. Some patients also have mental disorders. This tumor is considered the most dangerous, because it often transforms into a malignant one. However, in comparison with other types of pituitary tumors, it is much easier to identify it, since its signs appear already in the early stages.
Thyrotropinoma is the rarest type of pituitary tumor, as it occurs in only 1-2.8% of all cases of pituitary adenoma. In most patients, the formation of a tumor is accompanied by a malfunction of the thyroid gland. Due to the active secretion of thyroid-stimulating hormone, secondary hyperthyroidism is observed in patients.
Gonadotropinoma is a benign tumor accompanied by activation of the secretion of FSH and LH hormones. In rare cases, pathology proceeds without symptoms. The most characteristic signs of the tumor include ophthalmic and neurological disorders, hypogonadism and galactorrhea.
Diagnosis of pituitary adenoma
The diagnosis of this disease is carried out by three specialists: a neurologist, an ophthalmologist and an endocrinologist. The first two are usually treated in the case of ophthalmic-neurological syndrome, and the third in the case of endocrine-exchange syndrome. Nevertheless, for correct diagnosis and accurate diagnosis, the consultation of all these specialists will be required.
Radiography, MRI, CT
To identify the size of the tumor and its other characteristics, doctors resort to radiography of the Turkish saddle. This technique provides for a comprehensive study of the pituitary bone bed — its contours, shape and size. With its help, it is possible to identify signs such as double-contour of the bottom, osteoporosis, accompanied by the destruction of the back of the Turkish saddle. You can operate with more accurate data after an MRI of the brain and a CT scan of the skull.
Angiography
More than 20% of all pituitary tumors are too small to detect them using the above-mentioned techniques. Therefore, if the tomography did not reveal any neoplasms in the pituitary gland, but the clinical picture indicates them, the doctor may prescribe a brain angiography to confirm his assumptions.
Hormonal diagnostics
For a more detailed diagnosis of the disease, hormonal studies are also used, with the help of which it is possible to identify adenomatous growths. For this purpose, the following studies are usually prescribed: determination of the concentration of prolactin, chromogranins and somatotropic hormone, detection of free cortisol in urine, as well as its amount in peripheral blood, a test with dexamethasone.
Ophthalmological and laboratory tests
To detect ophthalmological disorders, an ophthalmologist’s examination, a visual acuity check, and ophthalmoscopy are prescribed. Laboratory tests also play an important role in the diagnosis of pituitary adenoma. The doctor prescribes a biochemical blood test and determination of the amount of glucose in it.
Treatment of pituitary adenoma
Therapeutic measures may include medication, radiation and neurosurgical methods. The choice of the most optimal methods of tumor treatment depends on several factors: the patient’s visual state, the nature of the growth and size of the tumor, the patient’s age, the presence of other serious diseases.
The type of tumor is also of significant importance. For example, radiation therapy to eliminate prolactinoma is ineffective. It is more suitable for the treatment of corticotropinomas smaller than 15 mm. Surgical techniques are used to remove corticotropin and somatotropin.
Medical treatment. Prescribing medications to a patient with a pituitary tumor is indicated to eliminate the symptoms of the disease and improve health. For this purpose, the doctor prescribes restorative drugs and vitamin complexes. Conservative treatment is indicated for small neoplasms. The selection of medications also depends on the type of tumor. With somatotropinomas, somatostatin agonists (somatulin and sandostatin) are prescribed, with prolactinomas — dopamine agonists and ergoline preparations, with corticotropinoma — steroidogenesis blockers (nizoral, mammomit, orimeten).
Radiation therapy. This technique is especially effective in microadenomas. Proton therapy, gamma therapy and remote therapy are often used to treat tumors. With this method of treatment, you can stop the growth of the tumor, and sometimes even achieve its regression.
Stereotactic radiosurgery. This is an innovative technique for the treatment of pituitary tumors, which involves the introduction of a radioactive substance into the pathological process. Compared with radiation therapy, this technique is more effective, since it avoids irradiation of the entire body.
Surgical treatment. The operation of pituitary adenoma is prescribed by a neurosurgeon after a comprehensive diagnosis. Indications for surgery may be large tumor sizes or complications such as cyst formation, hemorrhage, visual impairment. Microadenomas are usually removed by the transcranial method, which involves trepanation of the skull. The operation can also be performed transnasally using endoscopic techniques.
Prognosis of pituitary adenoma
Pituitary adenoma is a benign neoplasm. However, in the case of active growth, the tumor can transform into a malignant one. The size of the neoplasm affects the possibility of complete removal of pituitary adenoma. It has been proven that after the removal of a tumor with a size of two centimeters, there is a high risk of its recurrence over the next five years.
The prognosis of pituitary adenoma will also depend on the type of tumor. For example, 85% of patients with microcorticotropinomas have complete restoration of endocrine function after surgery. In patients with prolactinoma and somatotropinoma, these indicators are lower — about 20%. In rare cases, self-healing is observed in patients with prolactinoma.
