Pituitary tumors are tumors originating from the anterior and posterior pituitary lobes and the remnant cells of the craniopharyngeal duct epithelium. Pituitary tumors often have endocrine gland function and can cause a variety of endocrine function abnormalities.
Clinical manifestations
Pituitary tumors have the following three main clinical manifestations and one type of special manifestations after stroke.
1. Endocrine manifestations: Different types of pituitary adenomas may manifest as acromegaly, amenorrhea, lactation, infertility, headache, hypogonadism, etc.
2.Visual field disorders: early pituitary adenoma symptoms are often not obvious. As the tumor increases in size and extends upward to compress the visual cross, visual field defects may appear, with the outer upper quadrant being involved first, and gradually the defects may expand to bilateral temporal hemianopia. If the tumor is not treated in time, the enlarged visual field defect may be accompanied by visual acuity loss and eventually total blindness. If the tumor is biased to one side, it may lead to monocular blindness or blindness.
3. Other neurological signs: Depending on the direction of tumor growth, it may lead to different clinical manifestations. If the tumor grows posteriorly and presses the pituitary stalk or hypothalamus, it may cause polyuria; if the tumor grows laterally and encroaches on the lateral canal, it may cause nerve palsy of the motoneurium or abducens; if the tumor breaks through the saddle septum and grows upward to the ventral part of the frontal lobe, it may cause psychiatric symptoms; if the tumor grows posteriorly and presses the anterior part of the third ventricle and interventricular foramen, it may cause headache and vomiting and other symptoms of increased intracranial pressure. If the tumor grows backward, it can compress the brainstem and cause coma, paralysis or ankylosis of the brain.
4. Tumor stroke manifestation: In the process of tumor growth, due to poor vascular supply or abnormal growth of tumor blood vessels, tumor bleeding and necrosis of tumor tissues may occur, resulting in rapid increase of tumor volume.
Diagnosis
1.Endocrine examination
Most pituitary tumors have the function of secretion of hormones, early clinical manifestations are often not obvious, and imaging can not clearly indicate, but the level of pituitary hormones has changed, and some cases of pituitary tumors can be diagnosed by endocrine tests alone.
2.Imaging examination
(1) Cranial X-ray: This is a relatively primitive diagnostic method to determine the presence or absence of tumor and differential diagnosis according to the changes of the bone quality of the pterygoid saddle and calcification in the saddle area.
(2) CT scan: It has diagnostic value only for large pituitary tumors, and micro pituitary tumors are easily missed. It cannot be used as the main tool to diagnose pituitary tumor.
(3) MRI examination: It is the most important examination for the diagnosis of pituitary tumor, which can clearly show the size, shape, location and relationship with surrounding structures. With the popularity of high-definition MRI at 3.0T, even microadenomas of 2 to 3 mm can be clearly displayed.
Treatment
Current treatment for pituitary tumors includes surgical resection, radiation therapy, and medications. The majority of pituitary tumors are treated with surgery, which is relatively mature, with transnasal butterfly microscopic surgery and endoscopic surgery being the most common, while open surgery or combined transnasal butterfly and open surgery can be considered for more complex pituitary tumors. Radiation therapy is often used as an adjunct to surgery to control tumor growth and restore hormone levels. Drug therapy is mainly aimed at microadenomas and postoperative adjuvant therapy to adjust abnormal hormone levels and further shrink the tumor. This article focuses on the surgical treatment of pituitary tumors, which mainly includes open surgery and transnasal butterfly surgery.
Advances in surgical treatment
Craniotomy: Craniotomy to remove pituitary tumor has been used in clinical practice for a long time and is now a very mature procedure. The indications are as follows.
1) Huge pituitary adenomas that obviously invade to the frontotemporal lobe or even the posterior cranial fossa.
2) pituitary adenomas with significant narrowing of the connection between the part of the tumor developing suprasellarly and the intersaddle part.
3) pituitary adenomas whose tumors are fibrotic and hard and cannot be removed via the pterygoid sinus.
4) Patients who are not suitable for transsphenoidal surgery, such as huge pituitary adenomas, especially invasive ones; or patients who need combined access and staged surgery.
Transnasal butterfly surgery: mainly includes microscopic transnasal butterfly and endoscopic surgery, both of which are well established and are the most common surgical approaches for pituitary adenomas. The use of intraoperative neuronavigation is no longer a contraindication for patients with a previous contraindication to surgery, such as the mesenteric or anterior saddle type of pterygoid sinus. The indications for transsphenoidal surgical approach are
1) Tumor protrusion into the pterygoid sinus and confinement to the saddle.
2) vertical growth of the tumor into the suprasellar region.
Radiotherapy
Radiotherapy is often used as an adjuvant treatment to surgery. Conventional radiotherapy methods include X-ray radiotherapy, linear gas pedal X-knife, gamma knife and so on. Among them, gamma knife stereotactic treatment is the most common. Since pituitary tumors are fixed in position and sensitive to radiation, while normal pituitary cells are insensitive to radiation, gamma knife can often effectively kill tumor tissue without damaging or mildly damaging normal pituitary cells.
Comprehensive treatment
The objectives of pituitary tumor treatment are: to control hormone levels; to restore normal pituitary function; to shrink or even eliminate the tumor; and to eliminate the symptoms and signs caused by intracranial occupancy. For example, after surgical removal of most of the tumor, tumor growth can be controlled by radiotherapy or drug therapy; radiotherapy or drug therapy can shrink and soften the tumor before surgery, which can improve the efficacy and reduce the risk. With the continuous research on pituitary adenoma treatment, the combined application of surgery, drug, radiotherapy and multiple treatment methods has achieved better efficacy and has its unique advantages, which may become the future direction of pituitary adenoma treatment.