I. What is pituitary adenoma?
Pituitary adenoma, commonly known as “pituitary tumor”, is one of the common intracranial tumors, which is a benign tumor growing from the anterior lobe of pituitary gland. Most of them have endocrine function and thus can show some endocrine symptoms. Many patients first choose to go to endocrinology or oncology department and finally are referred to neurosurgery because of surgery; some patients first go to ophthalmology department because of vision loss and are also referred to neurosurgery because of surgery. According to the endocrine manifestation of the tumor, pituitary adenomas can be divided into prolactin adenoma (PRL tumor), growth hormone adenoma (GH tumor), adrenocorticotropin adenoma (ACTH tumor), and non-functional adenoma. According to the size of the tumor, it is divided into microadenoma (<1cm), macroadenoma (≥1cm) and giant adenoma (≥4cm).
What are the symptoms of pituitary adenoma?
1. Pituitary adenomas with endocrine function have different performances, mainly as follows.
(1) Growth hormone cell adenoma: It mainly manifests as excessive secretion of growth hormone. It can cause excessive growth and even become a giant, which is called “gigantism”. As an adult, the patient may show signs of acromegaly, such as facial changes, forehead enlargement, jaw protrusion, large nose and thick lips, thickened fingers, tightening of shoes and hats, replacing larger models several times, or even having to make them specially, some patients also have increased food intake, rough hair and skin, hyperpigmentation, and numbness of fingers. In severe cases, they feel general weakness, headache and arthralgia, hypogonadism, amenorrhea and infertility, and even complications of diabetes.
(2) Prolactin cell adenoma: The main manifestations are amenorrhea, overflow of milk, infertility, axillary hair loss, pale and delicate skin, increased subcutaneous fat, as well as fatigue, easy to tired, drowsiness, headache, and hypogonadism. In men, the symptoms include loss of libido, impotence, breast enlargement, beard thinning, and in severe cases, atrophy of reproductive organs, reduction of sperm count, and infertility.
(3) Adrenocorticotropic hormone cell adenoma: Clinical manifestations are centripetal obesity, full-moon face, buffalo back, polycythemia, purple lines on the skin of abdomen and thighs, and increased fine hair. In severe cases, amenorrhea, loss of libido, general weakness, and even bedridden. Some patients also have hypertension, diabetes, etc.
(4) Thyroid-stimulating hormone cell tumor: Rarely, hyperthyroidism is caused by the overproduction of thyroid-stimulating hormone in the pituitary gland, and the symptoms disappear after the pituitary tumor is removed. 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: It is very rare, and only some individuals report clinical hypogonadism, amenorrhea, infertility, and reduced sperm count.
(6) Melanin-stimulating hormone cell adenoma: Very rare, only a few patients reported black skin pigmentation without cortisol increase.
(7) Endocrine inactive adenoma: In the early stage, the patient has no special feeling that the tumor is growing and can compress the pituitary gland causing clinical manifestations of pituitary insufficiency.
(8) Malignant pituitary tumor: the disease history is short and the disease progresses rapidly. Sometimes the tumor penetrates the saddle base and grows into the pterygoid sinus, and 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, and the outer upper quadrant will be affected first. If the tumor is not treated in time, the visual field defect can be enlarged again and the visual acuity can be diminished to total blindness.
If the tumor grows backward, it may compress the brainstem and cause coma, paralysis or deactivation of the brain.
What tests should be done when pituitary adenoma is suspected?
1.Endocrinological examination: serum growth hormone (GH), IGF-1, prolactin (PRL), adrenocorticotropic hormone (ACTH), cortisol, thyroid stimulating hormone (TSH), T3, T4, melanin stimulating hormone (MSH), follicle stimulating hormone (FSH), luteinizing hormone (LH), etc. should be tested in hospital, which can help a lot in the early diagnosis of pituitary adenoma.
2.Imaging examination
(1) CT scan: After enhancement with intravenous contrast agent, it can show pituitary adenoma of 5mm size. For smaller tumors, it is still difficult to show.
(2) MRI scan: It is the most important and ideal means to examine pituitary adenoma, which can show the tumor morphology and its relationship with surrounding structures more clearly, especially valuable for the diagnosis of pituitary microadenoma, and is now the image that surgeons must read before surgery. For pituitary microadenoma, dynamic MRI scan should always be performed.
What diseases are easily confused with pituitary adenoma?
1.Craniopharyngioma: It occurs mostly in children and young people, with slow onset. In addition to visual acuity and visual field disorders, there are also manifestations of hypopituitarism and subthalamic involvement such as developmental arrest, sexual organ dysplasia, obesity and urinary collapse. Most of the tumors have cystic changes and calcification. The main body of this type of tumor is mostly located in the saddle, while the pituitary tissue is at the bottom of the saddle.
2.Saddle node meningioma: It occurs mostly in middle-aged people, with slow progression and initial symptoms of progressive vision loss with irregular visual field absence and headache, and endocrine symptoms are not obvious. Imaging performance tumor morphology is regular, enhancement effect is obvious, tumor is located in the suprasellar, pituitary tissue in the saddle bottom.
3.Lacrimal cyst: young age of onset, mostly no obvious clinical manifestations, a few appear endocrine disorder and vision loss. The imaging shows that small cysts are located between the anterior and posterior lobes of the pituitary gland, similar to a “sandwich” pie. In large cysts, the pituitary tissue is pushed into the inferior, anterior, and superior parts of the cyst. The disease is most likely to be misdiagnosed as a pituitary tumor.
4, germ cell tumor: also known as ectopic pineal tumor, mostly occurs in children, the disease develops quickly, polyuria, precocious puberty, wasting, clinical symptoms are obvious. The imaging lesions are mostly located in the saddle, and the enhancement effect is obvious.
5, optic cross glioma: mostly occurs in children and young people, with headache, vision loss as the main performance, imaging performance lesions are mostly located in the saddle, lesion boundary is unclear, mixed signal, enhancement effect is not obvious.
6, epithelioid cysts: young people, the onset of slow, visual impairment, imaging performance for low signal lesions.
V. What are the means to treat pituitary adenoma at present?
1.Surgical treatment: preferred (for most pituitary adenoma cases). Those with pituitary stroke (referring to symptomatic pituitary hemorrhage or infarction) or hydrocephalus should undergo emergency surgery. There are usually two types of surgery: craniotomy and transnasal-paranasal approach for pituitary adenoma resection. Transnasal-pterygoid sinus approach pituitary adenoma resection has been widely adopted internationally, and most patients are suitable for this procedure, which has the advantages of less trauma and better outcome. Note that not all pituitary adenomas need to be operated, some can be treated with medication; some do not necessarily need to be treated, but can be observed for a long time, and decisions need to be made under the consultation and guidance of an experienced doctor.
2.Stereotactic radiosurgery treatment: γ-knife or X-knife treatment can be considered for those without intracranial pressure increase sign and tumor diameter <2cm. However, such treatment should not be taken as the first choice after all. It is only suitable for those with particularly poor physical condition, recurrence even after multiple operations, postoperative residual or those who resolutely do not accept the surgery, and must be chosen with caution for the reason that there are more disadvantages.
3.Pharmacological treatment: Those with hypopituitarism can be given drug replacement therapy, and adenomas with secretory function can use drugs that inhibit excessive secretion of pituitary hormones as appropriate. Some of the adenomas with secretory function can be treated with drugs under the long-term guidance of doctors, such as most of the prolactin adenomas can be treated with long-term oral bromocriptine, and most of them can get good results. Growth hormone adenomas can be treated with growth inhibitors, and cycloheximide is indicated for ACTH adenomas and GH adenomas. Non-secretory functional adenomas can be treated with prednisone and thyroxine tablets to improve the symptoms of hypopituitarism, which can be used as needed.
What issues should be noted after the transnasal approach surgery (combined with a large number of practices in our hospital, for reference only)?
1. You can drink and eat on the next day after surgery, walk on the ground on the 2nd-3rd day, and generally be discharged from the hospital on the 6th-8th day.
2. Pay attention to reduce sneezing and violent coughing as much as possible within 2 weeks after surgery, and use drops of compound peppermint oil and other drops to spot bilateral nasal cavities.
3.It is advisable to eat easily digestible food within 1 month after surgery, and pay attention to dietary hygiene, prohibit overeating and drinking alcohol.
4.For 1 month after the operation, it is forbidden to do strenuous exercise, forbidden to have intercourse within 2 months, and forbidden to get pregnant within 3 months.
5.No nose picking within 2 months after surgery.
6.Retest MRI and pituitary hormone complete set 4 months after surgery.
7.If there is still excessive urination 2 weeks after surgery, it is advisable to check blood electrolytes 1-2 times a week at a nearby hospital for 1-2 months after discharge, and take anti-diaphoretic drugs under the guidance of the doctor.
8.For patients with cerebrospinal fluid leakage found intraoperatively, they should be bedridden for 1-3 weeks after surgery under the guidance of the doctor as appropriate.
9.Establish a long-term review relationship with the surgeon, and review at least once a year for 5 years after surgery.