Pituitary tumors are a group of tumors that occur from the anterior and posterior pituitary lobes and the epithelial remnants of the craniopharyngeal canal. Clinically significant symptoms account for approximately 10% of intracranial tumors. They are slightly more common in men than in women and usually occur in young adulthood, often affecting the patient’s growth and development, reproductive function, learning and work ability. Clinical manifestations include abnormal hormone secretion syndrome, tumor compression of peripituitary tissues, pituitary stroke and other hypopituitarism manifestations.
1.Abnormal hormone secretion syndrome Excessive hormone secretion syndrome, such as excessive growth hormone causing acromegaly; excessive hormone secretion syndrome. When a non-functional tumor enlarges and normal pituitary tissue is destroyed, amenorrhea occurs due to reduced gonadotropin secretion. Infertility or impotence often occurs earliest and is more common.
2.Tumor compression of peripituitary tissues (1) Nerve fiber irritation.
(2) Compression of optic nerve, optic cross and optic nerve bundle Patients present with visual acuity loss, visual field defects and fundus changes; other compression syndromes.
(3) Pituitary stroke.
4, Other manifestations of anterior pituitary hypoplasia.
Diagnosis 1.Clinical manifestations Patient’s age, gender, discomfort symptoms after the disease, physical changes.
2.Endocrine examination Since most pituitary tumors have the function of hormone secretion, when the clinical manifestation is not obvious and imaging cannot suggest a tumor yet, the pituitary tumor hormone has been changed. Some pituitary tumor cases can be diagnosed by endocrine test alone.
This is a relatively primitive diagnostic method to determine the presence or absence of tumor and differential diagnosis based on the changes of the bone quality of the pterygoid saddle and calcification in the saddle area.
(2) CT scan has diagnostic value only for large pituitary tumors, but small pituitary tumors are easily missed. It cannot be used as the main tool to diagnose pituitary tumor.
(3) MRI is the most important tool to diagnose pituitary tumor, which can clearly show the size, shape, location and relationship with the surrounding structures of the tumor. Even tumors with a diameter of 2 to 3 mm can be shown. However, there are some tumors whose signals are similar to the surrounding normal pituitary tissues, so it is difficult to distinguish between them.
4.Pathological examination This is the most reliable diagnostic method, and the misdiagnosis rate is very low.
Treatment 1.Comprehensive treatment The treatment of pituitary tumor mainly includes surgery, medicine and radiotherapy. It is because no one method can achieve complete cure, so each treatment method has its own advantages and disadvantages. Individualized treatment plan should be made according to the size of pituitary tumor, hormone secretion, complications and co-morbidities, the patient’s age, whether he/she has fertility requirements and the patient’s economic situation. The treatment of pituitary tumor is a comprehensive treatment process with multi-disciplinary collaboration.
2.Surgical treatment At present, the treatment of pituitary tumor is still mainly surgery, supplemented by drug therapy and radiation therapy. The location of pituitary tumor is in the saddle area, surrounded by the optic nerve, internal carotid artery, hypothalamus and other important nerve structures, so surgery still has certain risks. The current surgical methods include transsphenoidal sinus and craniotomy. If the tumor is larger than 3 cm in diameter and the optic nerve is adherent or the vision is impaired, surgery can be performed first. The surgery must achieve sufficient decompression of the optic nerve and then gamma knife treatment after surgery, but there is still a possibility of recurrence after surgery, so regular review is needed.
3.Radiotherapy Since pituitary tumor is an adenoma, its sensitivity to radiotherapy is poor, and 70%-80% of patients have reduced pituitary function after radiotherapy, which reduces the quality of life of patients, so radiotherapy is only suitable for patients with surgical residues, who cannot tolerate surgery, are not sensitive to drugs, and have co-morbidities that cannot be treated with surgery or drugs.
4.Medication For pituitary prolactin-secreting tumors, more than 90% of patients (either microadenoma or macroadenoma) can control PRL levels with dopamine agonists (short-acting agents bromocriptine, long-acting agents cabergoline) to reduce the size of the tumor. Surgical treatment is an option only for patients with prolactinomas who are allergic or intolerant to this class of drugs, who have acute symptoms due to tumor compression that require emergency surgical decompression, or for patients who do not wish to undergo surgical treatment. During treatment with bromocriptine, the dose of bromocriptine should be gradually increased until the serum PRL level drops to a normal level and then the dose is adjusted for long-term maintenance treatment.
Patients with growth hormone-secreting tumors, regardless of the treatment they receive, should achieve the following therapeutic goals: elimination of tumors, reduction of tumor recurrence, GH attainment, relief of clinical symptoms, preservation of pituitary function as much as possible, improvement of patients’ quality of life, and prolongation of patients’ life expectancy.
For growth hormone-secreting pituitary tumors, the main progress in the last 20 years has been the application of growth inhibitor analogs. The clinical application of this drug has led to a significant increase in the cure rate of GH-secreting tumors. In recent years, long-acting preparations of growth inhibitor analogs such as long-acting octreotide and somatuline have been used in the clinic, which has led to a significant improvement in patient compliance. Preoperative application of these drugs can rapidly reduce the patient’s serum GH level, alleviate the patient’s symptoms, reduce the size of the tumor, and create good preoperative conditions for the complete removal of the tumor. Additional indications for the use of growth hormone analogs in GH-secreting tumors include: postoperative residual patients, and transitional treatment of patients whose GH has not been reduced to normal after radiotherapy. The application of growth hormone analogs provides the opportunity for preoperative preparative therapy in patients who are unable to tolerate anesthesia due to concomitant heart failure, apnea, poorly controlled hyperglycemia, and hypertension. Satisfactory therapeutic results have also been achieved with growth hormone analogs for thyrotropin-secreting tumors.