What Can I Expect During Pituitary Adenoma Surgery?

Pituitary adenomas originate from the pituitary cells in the sphenoid saddle, and have a high incidence, accounting for about 12% of intracranial tumors. Most of them are benign. They are more common in middle-aged people, and there is no significant difference in male to female ratio. Those whose tumor diameter is less than 1cm and confined to the saddle are called microadenomas; those who break through the saddle septum with a diameter of 1-3cm are called large adenomas; those who are more than 3cm in diameter and extend to the side of the saddle and the lower parietal are called giant adenomas. Giant adenomas can develop into the third ventricle from the saddle, and can reach the cavernous sinus to the sphenoid saddle, extending into the middle cranial fossa. It can grow back into the footwells and slopes, and can penetrate the saddle bottom down into the sphenoid sinus or nasopharynx. According to the classification of tumors by acid-base staining, pituitary adenomas are classified into chromophoblastic adenomas, eosinophilic adenomas and basophilic adenomas, mixed adenomas, and malignant adenomas. Malignant adenomas grow rapidly, are large, and infiltrate widely around them. Tumor cells vary in size and have mitosis.

Pituitary adenomas originate from the pituitary cells in the sphenoid saddle, and have a high incidence, accounting for about 12% of intracranial tumors. Most of them are benign. They are more common in middle-aged people, and there is no significant difference in male to female ratio. Those whose tumor diameter is less than 1cm and confined to the saddle are called microadenomas; those who break through the saddle septum with a diameter of 1-3cm are called large adenomas; those who are more than 3cm in diameter and extend to the side of the saddle and the lower parietal are called giant adenomas. Giant adenomas can develop into the third ventricle from the saddle, and can reach the cavernous sinus to the sphenoid saddle, extending into the middle cranial fossa. It can grow back into the footwells and slopes, and can penetrate the saddle bottom down into the sphenoid sinus or nasopharynx. According to the classification of tumors by acid-base staining, pituitary adenomas are classified into chromophoblastic adenomas, eosinophilic adenomas and basophilic adenomas, mixed adenomas, and malignant adenomas. Malignant adenomas grow rapidly, are large, and infiltrate widely around them. Tumor cells vary in size and have mitosis.

Chinese name

Pituitary adenoma

Foreign name

pituitary adenoma

Causes and common diseases of pituitary adenoma

Early pituitary adenomas, especially microadenomas, have few clinical manifestations, and gradually develop symptoms such as endocrine disorders and nerve compression.

Due to the increase in adenoma volume, the pituitary tissue outside the tumor is compressed and atrophied, resulting in reduced secretion of other pituitary hormones and atrophy of the corresponding surrounding target glands. Most of the clinical manifestations are complex, sometimes with hypogonadism, sometimes with secondary hypothyroidism, occasionally with secondary adrenal insufficiency, and sometimes tumors compress the posterior pituitary or hypothalamus to produce diabetes insipidus. . Due to the increased levels of the corresponding hormones secreted by various pituitary adenomas, anterior pituitary hyperfunctions can occur, such as giant disease and acromegaly, cortisol, and galactorrhea-amenorrhea syndrome.

Neurological symptoms are caused by tumor compression, mainly including:

1. Headache: Forehead or bitemporal headache due to the expansion of the saddle septum, a small number of patients may have headaches on one side of the eye or on the frontal side. When the tumor continues to grow and the saddle septum is destroyed, the headache disappears. Increased intracranial pressure may cause intracranial hypertension headache, which is rare.

2. Vomiting: Vomiting may occur if intracranial hypertension occurs.

3, vision loss, visual field defect and fundus changes: tumors grow forward and upward, often oppressing the optic cross, optic nerve, 70% to 80% of patients may have varying degrees of visual loss, visual field defects and fundus changes. Vision loss can be unilateral or bilateral, or even blindness; visual field changes can be unilateral or bilateral temporal blindness, and a few can produce nasal visual field defects. Usually, the visual field in the upper quadrant of the patient's eye is damaged first, then stretches towards the point of fixation, and develops into the lower temporal quadrant. The fundus showed progressive lightening of the optic nerve, the optic nipples showed atrophy of varying degrees of primary, and a few may have optic nerve nipple edema.

4. Other oppressive symptoms: advanced tumors can oppress the oculomotor nerve, abductor nerve, trigeminal eye branch, or the cerebral foot or cerebral hemisphere, causing symptoms of one or both pyramidal tracts.

5. Special symptoms: Patients with pituitary adenoma may sometimes have some special symptoms, which are rare clinically.

(1) Epilepsy: Patients may experience a major seizure, which may be the result of an endocrine disorder.

(2) Cranial nerve palsy: When pituitary adenoma compresses the cavernous sinuses on both sides, it can cause nerve damage such as one or two eye movements, abduction and trigeminal eye branch (cavernous sinus syndrome). appear.

(C) Cerebrospinal fluid rhinorrhea: When the tumor grows down and destroys the saddle bottom or sphenoid sinus, it can cause cerebrospinal fluid rhinorrhea and can also be accompanied by meningitis.

(4) Tremor palsy syndrome: Tumors compress striatum on one or both sides can cause tremor paralysis syndrome.

(5) Pituitary stroke: Pituitary adenoma is a blood-rich tumor with extensive necrosis and blood vessel rupture, which leads to subarachnoid space or intracerebral hemorrhage. This condition is called pituitary stroke. A few patients can have bleeding as a first symptom.

Due to endocrine changes and neurological changes, pituitary adenomas can develop mental disorders, and tumors that expand upwards affecting the third ventricle produce special mental symptoms of mesencephalic tumors. Hecean believes that it is one of the few psychiatric symptoms that are important to the clinical practice of neurosurgery. It is manifested as: can not remember recent events or newly learned things, upside down, but retains good memory of distant events or other cognitive abilities, Obvious fiction can occur; consciousness damage, mental decline, mental and physical activity retardation, irritability, depression, euphoria and other emotional disorders as well as irresponsibility, childishness, lack of self-awareness can occur when the tumor expands and affects the frontal lobe. Personality changes; tumors expanding outward and involving the temporal lobe can also produce corresponding mental symptoms such as temporal lobe epilepsy, etc. White and others have pointed out a series of mental disorders of pituitary tumors: hypothalamic dysfunction with lethargy, limited amnesia, personality decline, Seizures, sluggishness, apathy, and passiveness, as well as mental retardation that is not parallel to the increase in intracranial pressure, don't care about the illness, emotional instability, and paranoia.

Differential diagnosis of pituitary adenoma

1. Diagnosis of pituitary tumor;

2. Identify the type of pituitary adenoma;

3. Understand pituitary function and surrounding tissue damage.

According to the clinical manifestations, X-ray findings (choose the head and lateral radiography and tomography, CT, pneumoencephalography, cerebral angiography, etc.) and endocrine examination to confirm the diagnosis. Adenomas with endocrine function have their own clinical manifestations and endocrine characteristics; non-functioning patients should pay attention to the tumors adjacent to the saddle and cancers and sarcoidosis, eosinophilic granuloma, tuberculoma that metastasize to the pituitary from other parts of the body, etc. Identification. Craniopharynx and tuberculoma usually develop in children, grow slowly, and are characterized by calcification points on the saddle.

Pituitary adenoma examination

Most pituitary adenomas are single, and the tumors can be large or small. Those with a diameter of less than 10mm are called micro-adenoma, and those with a diameter of more than 10mm are called ma-croadenoma. The surface is smooth and has a complete envelope. Erosion and compression of the optic nerve cross, hypothalamus, third ventricle and nearby brain tissue, and sponge sinus. Small adenomas are often hidden in the saddle and do not compress the saddle and surrounding tissues. Clinically, only endocrine symptoms may be asymptomatic. Occasionally, tumors can erode the sphenoid bone and damage bone and grow into the nasopharynx.

The electron microscope showed that the intracellular particles of auxin adenomas and prolactin adenomas are larger and can be divided into two types: dense and sparse. Prolactin adenomas have the largest intracellular particles, with a diameter of 600 to 1200 nm. Dislocation exocytosis of secreted particles can be seen away from blood vessels between cell membranes. The auxin adenoma cells have the second largest intracellular granules, with a diameter of 350-450 nm. The rough endoplasmic reticulum is abundant and the Golgi complex is well developed. Corticotropin adenoma cells are spherical or polygonal, with a round or oval nucleus, rich rough endoplasmic reticulum and ribosome, a distinct Golgi complex, 7nm flagella accumulation around the nucleus, and Crooke hyaline degeneration, Thyroid stimulating adenoma is composed of closely-arranged polygonal or slightly longer cells with few particles and a minimum diameter of 100-200 nm. There is a halo between the particle and the envelope, and there are a large number of microtubules in the cytoplasm. Gonadotropin is a granular rare undifferentiated adenoma whose cell chromosome is proved to be a follicle stimulating adenoma. Mixed tumors are characterized by the simultaneous presence of multiple cells. From the morphology of electron microscope, it is still difficult to separate their secretory functions. The secretory functions of different cells can be identified only by immunohistochemical identification combined with electron microscopy.

Pituitary adenoma treatment principles

Can be treated with surgery. Surgical approach mainly includes transfrontal craniotomy tumor resection; microadenomas can be removed microscopically through the oronasal approach. In addition, radiation therapy (including gamma knife technology) can be performed. The drug treatment is mainly bromocriptine, which can stimulate dopamine receptors in pituitary cells to reduce plasma prolactin, and has the function of restoring menstruation and inhibiting galactorrhea.