Pituitary tumors are tumors that occur in the pituitary gland and are often referred to as pituitary adenomas. They are one of the common neuroendocrine tumors and account for approximately 10-15% of central nervous system tumors. The vast majority of pituitary adenomas are benign tumors.
Introduction
Pituitary adenomas are benign adenomas that are quite common and have a high incidence in the general population. With the improvement of diagnosis, the incidence of pituitary adenomas has increased in recent years, especially in women of childbearing age.
Clinical manifestations
The pituitary gland is an important endocrine organ, containing several types of endocrine cells that secrete a variety of endocrine hormones. About 40% of pituitary tumors are non-secretory pituitary tumors, which only produce symptoms of tumor pressure. 60% of pituitary tumors are functional pituitary tumors, and special clinical manifestations may occur if an endocrine cell grows adenoma. Their details are described separately as follows.
1. Endocrine manifestations of different kinds of functional pituitary adenomas
(1) Growth hormone cell adenoma.
Microadenomas are only a few millimeters in size and mainly manifest as excessive secretion of growth hormone. The growth rate may be too fast in immature patients, which may manifest as gigantism. In adulthood, it is a manifestation of acromegaly. For example, the face changes, the forehead becomes bigger, the jaw protrudes, the nose is big and the lips are thick, the fingers become thicker, the shoes and hats feel tighter, the larger models are changed several times, and even have to be specially made. In severe cases, they feel general weakness, headache and arthralgia, hypogonadism, amenorrhea and infertility, and are prone to complications such as diabetes, hypertension and even certain types of malignant tumors.
(2) Prolactin cell adenoma.
The main manifestations are amenorrhea, overflow of milk, infertility, loss of axillary hair, pale and delicate skin, increased subcutaneous fat in severe cases, as well as weakness, easy tiredness, drowsiness, headache, and hypogonadism. In men, the symptoms include loss of libido, impotence, breast enlargement, beard thinning, atrophy of reproductive organs, reduction of sperm count and infertility, etc. There are not many male and female patients.
(3) Adrenocorticotropic cell adenoma.
Clinical manifestations are centripetal obesity, full-moon face, buffalo back, polycythemia, purple lines on the skin of abdomen and thighs, and increase in fine hair. In severe cases, amenorrhea, loss of libido, general weakness, or even bedridden. Some patients also have hypertension, diabetes, etc.
(4) Thyroid-stimulating hormone cell tumor.
Rarely, hyperthyroidism is caused by excessive secretion of thyroid-stimulating hormone from the pituitary gland, which disappears after removal of the pituitary tumor. The symptoms of hyperthyroidism disappear after removal of the pituitary tumor. There are also cases of focal hyperplasia of the pituitary gland caused by hypothyroidism feedback, which gradually develops into pituitary adenoma.
(5) Follicle-stimulating hormone cell adenoma.
Very rare, only isolated reports of clinical hypogonadism, amenorrhea, infertility, and reduced sperm count.
(6) Melanin-stimulating hormone cell adenoma.
Very rare, with only isolated reports of dark skin deposits without cortisol increase.
(7) Endocrine inactive adenoma.
Early patients have no special sensation of tumor growth and may compress the pituitary gland causing clinical manifestations of pituitary insufficiency.
(8) Malignant pituitary tumor.
Short history and rapid progress of the disease, not only the tumor grows to compress the pituitary tissue, but also invades to the surrounding area, causing the destruction of the bone of the saddle base or infiltrating into the cavernous sinus, causing the paralysis of the motoneurotic nerve or abducens nerve. Sometimes the tumor penetrates the saddle base and grows into the pterygoid sinus, but the neurological symptoms are not obvious for a short period of time.
2.Visual field disorder.
Early pituitary adenoma often has no visual field disorder. If the tumor grows up and extends upward to compress the visual cross, visual field defect will appear. If not treated in time, the visual field defect can be enlarged again, and the visual acuity can be reduced to total blindness. Because pituitary tumor is mostly benign, the initial lesion can last for quite a long time, but when the condition is serious, the visual field impairment can suddenly increase, and if the tumor is on one side, it can cause monocular blindness or blindness.
3. Other neurological symptoms and signs.
If the pituitary tumor grows upward and presses the pituitary stalk or hypothalamus, it may cause excessive drinking and urination. If the tumor grows posteriorly, it may compress the brainstem and cause coma, paralysis or deactivation of the brain.
Auxiliary examination
How to detect pituitary tumor early
It is important to pay attention to the symptoms after they appear, such as a CT examination, and then a more detailed MRI examination can clarify. Generally speaking, if the endocrine changes are not effective after treatment, or if there is headache, visual impairment, or endocrine any of them should be considered, and if they occur at the same time, they should be examined in time. Pituitary tumors are usually found in women aged 20-40 years old, because women have more hormonal changes and fluctuations during their lifetime.
1. Endocrinological examination.
The application of endocrine radioimmuno-ultra-microscopic method to directly measure growth hormone, prolactin, adrenocorticotropic hormone, thyroid-stimulating hormone, melanin-stimulating hormone, follicle-stimulating hormone and luteinizing hormone in pituitary gland is very helpful for early diagnosis of pituitary adenoma.
2.Radiological examination
Cranial magnetic resonance examination is the best method to diagnose pituitary adenoma. For patients with metallic foreign bodies in the body, cranial enhancement CT can be performed for diagnosis.
3.Ophthalmic examination.
For patients with pituitary tumor, visual acuity, visual field, fundus and eye movement should also be examined to determine the extent of tumor’s influence on optic nerve, optic cross and cavernous sinus.
Treatment measures
1.Surgical treatment.
It mainly includes craniotomy and transsphenoidal sinus surgery treatment. At present, most pituitary tumors can be treated by transnasal surgery, among which transnasal surgery via neuroendoscope is the mainstream surgical method at present, which has the advantages of small trauma, clear exposure and high rate of total incision.
2.Drug treatment.
Bromocriptine is a semi-synthetic ergotamine alkaloid, which can stimulate the dopamine receptors of pituitary cells to reduce the effect of prolactin in blood. Bromocriptine can reduce the size of prolactin adenoma, restore menstruation and ovulation and conception, and also inhibit pathological overflow, which is currently recommended as the first-line treatment for general lactogenic adenoma. For growth hormone adenoma, growth inhibitor analogs have been used for perioperative treatment of growth hormone and can be used as a second-line treatment option.
3.Radiotherapy.
Stereotactic radiation therapy can be used for the treatment of microscopic non-functional adenomas and residual tumors after surgery, but it is slow to work and can easily lead to complications such as pituitary hypofunction.