Prolactinoma of the pituitary: Symptoms, treatment and prognosis
Prolactinoma is a benign tumor( adenoma) of the anterior lobe of the pituitary gland.It is characterized by hormonal activity, that is, it synthesizes an increased amount of prolactin( luteotropic hormone).
Prolactinoma occupies the first place in the structure of pituitary neoplasms.The share of these adenomas accounts for over 30% of diagnosed tumors of this endocrine gland.Table of Contents: Characteristics and Classification Causes of Tumor Obstruction Symptoms of Prolactinoma of the Pituitary
Characteristics and Classification of
Important: Malignant prolactin is rare.Most often these adenomas are diagnosed in women of fertile age.In men, such tumors are detected almost 10 times less often.
Neoplasm develops from prolactotrophs - pituitary cells that synthesize the "milk hormone". In most cases, the size of hormone-active adenomas of the pituitary gland does not exceed 2-3 mm in diameter.
Prolactin production is controlled by the hypothalamus.Dopamine, produced by its nuclei, suppresses the secretory function of lactotrophs.
Note: Prolactin is a polypeptide hormone responsible for the synthesis of breast milk in women in the postpartum period.In addition, it has a regulating effect on sexual and reproductive functions, along with luteinizing and follicle-stimulating hormones( LH and FSH).These biologically active compounds are responsible for menstruation, ovulation and synthesis of estrogens.A certain amount of prolactin, LH and FSH is normally synthesized in the body of a man.Gonadotropic hormones affect the production of testosterone and the degree of activity of spermatozoa.
In clinical practice prolactin size and localization is used with respect to Sella turcica( "Turkish saddle") - formation in the sphenoid bone, in the center of which is the pituitary fossa. According to her, these adenomas are divided into:
- Intrasellar( their diameter does not exceed 1 cm).
- Extrasellar( diameter ≥ 1 cm).
Microprolactinomas are more common in women, and macroprolactinomas are for men .The size of the adenomas greatly affects the severity of clinical manifestations.The type of treatment depends on the type of tumor.
Reasons for the appearance of the tumor
Currently, there is no reliable information on the true causes of prolactinoma formation.
The hereditary predisposition of is of definite importance;In some patients with benign pituitary tumors, a genetic disorder is diagnosed - multiple endocrine neoplasia of type I.This pathology is characterized by increased secretory activity of a number of endocrine glands.
Symptoms of prolatonnoma of the pituitary
Against the backdrop of tumor development, hyperprolactinaemia develops, resulting in the suppression of the formation of female sex hormones, the absence of ovulation and, as a consequence, infertility.
Typical clinical symptoms:
- galactorrhea( excretory breast milk not related to childbirth);
- amenorrhea( or irregular monthly);
- gynecomastia( an increase in mammary glands in men);
- erectile dysfunction, decreased sexual desire and potency( in men).
Growth of prolactinoma, accompanied by compression of the brain structures, may be accompanied by the appearance of headaches, impaired consciousness and visual perception disorders.
Macro-prolactinomas( large neoplasms) often cause compression of the eye nerves, which is manifested by diplopia( double vision), narrowing of the visual fields and the appearance of problems with recognition of objects located on the side.If such a tumor presses on chiasma opticum( cross of the optic nerves), complete blindness is possible.
Neurological symptoms with large prolactinomas:
- unmotivated sense of anxiety;
- increased irritability;
- high emotional lability( frequent changes of mood).
Compression of the pituitary leads to a violation of the production of its other hormones - somatotropic, thyrotropic, adrenocorticotropic, luteinizing and follicle-stimulating.
Symptoms typical for women
The early signs of prolactinoma include the prolongation of the menstrual cycle or the complete absence of menstruation . Decreased production of LH and FSH leads to anovulation, which makes conception impossible.
The intensity of the galactorrhea is variable.Milk can appear only when pressing on the nipple area or stand out spontaneously.
Important: , milk production in the pituitary tumor is not related to breast pathology, but against their background, the galactorrhea becomes an additional risk factor for mastopathy.
Hyperprolactemia promotes leaching of mineral components from bone tissue.As a consequence, osteoporosis develops, often leading to pathological fractures.
Important: osteoporosis with prolactinoma appears in both women and men.
Deficiency of female sex hormones due to excess prolactin provokes metabolic disorders( fluid retention in the body and obesity).
Prolactinoma in some cases is accompanied by hypersecretion of male sex hormones.In this case, the patient has symptoms such as acne( acne) and hirsutism( excessive hair growth in the male type).
Symptoms typical for men
Hyperprolactemia leads to a decrease in the production of the main androgen - testosterone and a violation of the development of spermatozoa leading to infertility .In men, the libido weakens or completely disappears and the erectile function is disturbed.In most cases, patients are diagnosed with gynecomastia.
The enlargement of the mammary glands can be accompanied by a galactorrhea.In a number of patients, hair growth on the face decreases and the process of atrophy of the sex glands - the testicle - is going on.Other characteristic manifestations include muscle weakness.
Diagnosis of prolactinoma
To suspect a benign pituitary tumor, characteristic clinical symptoms allow.
The most informative method for the diagnosis of prolactin is aimed magnetic resonance scanning with the preliminary introduction of the contraindicant .This hardware technique allows you to objectively assess the location and size of the tumor.
Computed tomography can be used to detect macropolylactinoma, providing a clear visualization of the structures of the sphenoid bone.
Laboratory diagnostics presupposes a threefold determination of prolactin levels in plasma.The study is conducted on different days to avoid possible errors related to the psychoemotional stress of the patient.
Normal digits( in ng / ml):
- for men & lt;15;
- for women & lt;20.
Indicators above 200 ng / ml allow a high probability of talking about the presence of a hormone-active tumor.
Concentration within 40-100 ng / ml requires differential diagnosis to exclude other possible factors for the onset of hyperprolactinemia - hypothyroidism, renal and hepatic insufficiency, drug stimulation of prolactin synthesis, pregnancy and dysfunction of the hypothalamic-pituitary system.
A test with tyroliberin is very indicative.With the introduction of this substance( IV) in a healthy person, after a quarter of an hour the level of synthesis of prolactin increases 2 or more times.In the presence of an adenoma, there is no reaction to tyroliberin, or the prolactin level increases less than 2-fold.
In case of violations of the visual function, consultation of an ophthalmologist is required.Densitometry can detect osteoporosis.
Prolactinoma treatment and prognosis
The medical tactic is determined by the activity of prolactinoma.According to the indications, conservative treatment or surgical intervention is performed.
Standard therapy involves measures to reduce prolactin levels with pharmacological agents . drugs are selected individually, and the scheme of their reception is determined by the endocrinologist.
The most effective drugs for the treatment of prolactin:
Bromocriptine therapy has a positive effect in 85% of cases.After several weeks of course treatment, the level of "milk hormone" returns to normal.
Most often the preference is given to Cabergoline;This drug has fewer side effects, and the prolonged nature of the action allows you to take it 1-2 times a week.
Pharmacotherapy can reduce the diameter of the tumor and restore vision. Microprolactinomas in some cases disappear.The drugs restore the menstrual cycle and return fertility.In male patients, the spermogram index improves, and the sexual function due to the normalization of testosterone production comes back to normal.
Radiotherapy makes it possible to gradually abandon the use of pharmacological agents, but the positive effect of exposure to ionizing radiation is fully developed only after several years.One of the side effects of irradiation is pituitary insufficiency, requiring replacement hormone therapy.
When conservative therapy with large prolactin is carried out periodic monitoring by means of tomography. If a positive effect is not achieved, resort to surgery - adenomectomy.The removal of the neoplasm is carried out through a small incision in the projection of the nasal sinuses.
Prolactinomas are prone to recurrence;Complete clinical recovery occurs only in 25% of patients.The least favorable prognosis is with macroprolactinomas and adenomas subjected to malignancy.
Almost half of patients have relapses within 5 years after surgery.
Vladimir Plisov, medical reviewer