Pediatric craniopharyngioma
Introduction
Introduction to pediatric craniopharyngioma Craniopharyngioma (craniopharyngioma) originates from the squamous epithelial cells remaining in the pituitary embryogenesis. It is a common congenital intracranial benign tumor, mostly located on the sella, a few in the saddle, and the craniopharyngioma Many names, related to the starting site and growth, such as saddle cyst, cranial buccal tumor, pituitary tube tumor, ameloblastoma, epithelial cyst, enamel and so on. The onset of craniopharyngioma is mostly in children and adolescents. The main clinical features include hypothalamic-pituitary dysfunction, increased intracranial pressure, visual and visual impairment, diabetes insipidus, and neurological and psychiatric symptoms. CT scans can confirm the diagnosis. The main treatment is surgical removal of the tumor. At the end of the 19th century, some pathologists noticed a rare type of epithelial tumor that grew in the sellar region, suggesting that this type of tumor may originate in the pituitary or cranial sac. In 1904, Erdheim described the histological features of the tumor in detail and thought that the tumor might come from the degenerative pituitary gland - the epithelial cells of the embryo of the pharynx. Later, it was found that the growth of craniopharyngioma was along the path of the cranial sac, from the pharynx to the saddle, the saddle, the saddle and the front of the third ventricle. Some people have noticed the difference between adult and childhood craniopharyngioma, and believe that adult tumors are not embryogenic, but tissue transformation after birth in pituitary cells, because there are squamous epithelial cells in the pituitary, but this explanation still Lack of evidence, in 1910 Lewis first tried to remove this type of tumor. The name of craniopharyngioma began to be universalized after 1918. basic knowledge Probability ratio: craniopharyngioma accounts for about 4% of intracranial tumors Susceptible people: children Mode of infection: non-infectious Complications: coma, disturbance of consciousness, epilepsy, diabetes insipidus, gastrointestinal bleeding
Cause
Causes of pediatric craniopharyngioma
Congenital (30%):
This is a widely accepted theory of histogenesis. Erdheim first observed residual squamous epithelial cells in the nodules of the normal pituitary. It is believed that craniopharyngioma originated from these residual epithelial cells during the second week of the embryonic period. The original oral cavity tops up to form a deep blind bag called Rathke bag. As it develops further, the lower part of the Rathke bag becomes narrow and has a thin tube shape, which is called a craniopharynx tube or a pituitary tube. Under normal circumstances, The cranial pharynx disappears gradually from 7 to 8 weeks after the embryo, and there is often a small nest of epithelial cells in the development process, which becomes the tissue source of craniopharyngioma.
Squamous metaplasia (20%):
In 1955, Luse and Kernohan observed 1364 autopsy pituitary glands, and found that only 24% had squamous cell nests, and their incidence increased with age. The incidence of squamous cell nests was lower in people under 20 years old. Therefore, they believe that the squamous cell nest is a product of pituitary cell metaplasia, not embryonic residue. In addition, people have observed a mixture of pituitary gland cells and squamous epithelial cells, and there is an excess between them. The discovery also supports the metaphysical doctrine.
Pathological changes:
The volume of craniopharyngioma is generally large, and the shape of the tumor is often spherical, irregular, or nodular, with no obvious envelope, clear boundaries, and obvious differences in range. Most of them are cystic multi-atrial or partial cystic. A few are substantial, only a small number of small cysts, the tumor is grayish red, the cyst fluid can be yellow, brown, brown or colorless, such as cyst rupture, cyst fluid overflow, can cause meningitis and arachnoiditis, cystic Most of them are located on the saddle, and the cystic part is often above the parenchyma. The surface of the capsule wall is smooth and the thickness is different. The thin one can be as translucent, with many grayish or yellowish brown calcifications or calcified spots on the bone. It is eggshell-like, and the content of the capsule is degraded liquefied epithelial cell debris (keratin-like substance). The cystic fluid is oily or golden yellow liquid, containing flickering and floating cholesterol crystals, generally 10 to 30 ml, many can be Up to 100ml or more, the tumor parenchyma is often located in the posterior and inferior, in a nodular shape, containing calcification, sometimes dense and hard, often associated with intracranial important blood vessels, pituitary stalk, visual pathway and anterior third ventricle adhesion and compression The above structure, the tumor can also cause The glial reaction zone of the brain tissue forms a pseudo-envelope, sometimes protruding into the hypothalamus, and may cause damage to the hypothalamus when the tumor is pulled by surgery. The substantial tumor is located in the saddle or the third ventricle, and the volume is more cystic. Small.
Tumor tissue morphology can be divided into two types: enamel type and scaly type. The enamel type is more common, mainly in children. The outermost layer of this type is columnar epithelial cells, which gradually move toward the center and the outer layer is fence-like. The stratified cells are arranged in loose stellate cells. The tumor tissue often has degenerative changes, keratinization and small cysts. After the detached cells in the sac absorb calcium, many scattered calcifications are prominent features of the craniopharyngioma. Almost all craniopharyngioma Calcification can be seen under the microscope. In most cases, calcification can be found during radiology. The craniopharyngioma often protrudes from the papillary into adjacent brain tissue (especially the hypothalamus), making the tumor closely connected with these brain tissues. Therefore, the operation is often not easy to completely remove. The scaly papilla type is composed of well-differentiated squamous epithelial cells, which are rich in fibrovascular matrix, and the cell membrane is naturally cleaved or a pseudo-papillary shape is formed due to the cracking of the lesion. Non-enamel type keratinized beads, calcification, inflammatory reaction and cholesterol deposition, this type is mostly solid tumors, occasionally reported craniopharyngioma grows rapidly, invasive recurrence, but Mathematics were not considered to be malignant transformation, some of the electron microscope anaplastic tumor manifestations, in tissue culture despite the tendency to balloon, but almost no mitotic activity.
There are differences in the location of blood supply to craniopharyngioma. The blood supply to the tumor on the saddle is mainly from the small artery of the anterior circulation of the Willis ring. It is also thought that there is blood supply directly from the internal carotid artery and the posterior communicating artery, but the craniopharynx The tube tumor does not receive blood supply from the posterior cerebral artery (or basilar artery) unless the tumor is close to the bottom of the third ventricle where the blood vessel supplies blood. The blood supply to the tumor inside the saddle is from the small penetrating artery of the internal carotid artery of the cavernous sinus.
The tumor grows around and can oppress the optic nerve, the pituitary gland, the bottom of the third ventricle, the hypothalamus, and even block the interventricular pores on one or both sides to cause obstructive hydrocephalus. Most of the saddle-type tumors are substantial and volume. Small, early limited to the saddle can directly compress the pituitary, and later growth can affect the optic nerve, the optic chiasm and the third ventricle.
Prevention
Pediatric craniopharyngioma prevention
1. For patients with high intracranial pressure, dehydrating agents and diuretics should be given immediately to reduce intracranial pressure. Such patients should be prepared as soon as possible for surgery.
2. Before surgery, patients with hypopituitarism should pay attention to replenish a sufficient amount of glucocorticoids to avoid pituitary crisis. Other pituitary hormones may not be replenished, because many patients may recover from postoperative pituitary function. If there is still hypopituitarism after surgery, appropriate treatment should be given.
Complication
Pediatric craniopharyngioma complications Complications, coma, dysfunction, epilepsy, diabetes insipidus, gastrointestinal bleeding
Craniopharyngioma has a slow growth and a long course of disease, which mainly damages the structure of the lower and surrounding hypothalamus, causing endocrine dysfunction, visual acuity, visual field damage and increased intracranial pressure. The treatment is mainly surgery. Common postoperative complications are as follows:
1. Central hyperthermia: The patient's high fever persists, is in a coma state, and has a poor prognosis. It is usually treated symptomatically. The reasons may be:
1 The hypothalamic function is impaired when the craniopharyngioma is removed, causing hyperthermia due to thermoregulatory dysfunction;
2 The cystic fluid in the cystic tumor stimulates the meninges and hypothalamus to produce aseptic meningitis;
3 surgery caused by bloody cerebrospinal fluid stimulation caused by fever.
Closely observe the heat type and duration after surgery, distinguish between central hyperthermia and lungs, high fever caused by urinary tract infection, and use hypnotic drugs with caution in patients with fever to prevent disturbance of consciousness, post-head pillow ice pack, ice cap or body ice The blanket, continuous anal temperature monitoring, body temperature is quickly controlled below 38.5 °C, which is caused by hypothalamic injury during surgery.
2. Consciousness disorder: mainly caused by impaired hypothalamus or increased intracranial pressure, and increased intracranial pressure:
1 postoperative blood clot obstruction of the aqueduct to hydrocephalus;
2 surgical hemostasis does not completely cause subdural hematoma or epidural hematoma;
3 Surgical stimulation or electrolyte disturbance causes secondary cerebral edema. Nurses should closely observe changes in the patient's mind and pupils. In particular, observe the patient's nausea, vomiting and wound tension, neck stiffness and other symptoms within 72 hours after surgery. Keep the drainage tube. Smooth, pay attention to observe the color and quantity of drainage fluid. For those with conscious disturbance, use Glasgow coma scoring method to evaluate the degree of consciousness, timely discover and timely and correct treatment.
3. Diabetes insipidus: This complication is almost inevitable in patients with total tumor resection or radical subtotal resection. It is caused by injury to the pituitary stalk during operation. After the pituitary stalk is damaged, the release of ADH is three-phase. Initially, the release of ADH after the pituitary stalk is damaged reduces the collapse of the urine; after that, the degeneration of the axonal extremity of the pituitary gland releases a super-physiological amount of ADH. This release process is usually 48 to 96 hours after the pituitary stalk injury. Anti-diuretic preparation (usually given to short-acting vasopressin) may cause endogenous release of ADH and cause renal function decline; when hormones released from degenerated nerve endings are depleted, urine will reoccur Collapse, general diabetes insipidus can last for several days to 2 weeks, but there are also a few can be permanent diabetes insipidus, the treatment is as follows:
(1) Focus on observing patients with polydipsia, polyuria, polydipsia and other urine output, urine specific gravity, record 24h in and out, according to the amount of fluid added to the liquid, urine volume <5000ml / d, can be used without drugs, conscious people Drink more water; demented, 2 to 3 hours after surgery to give indwelling stomach tube, add water and nutrition, urine volume > 5000ml / d, urine specific gravity <1.005, subcutaneous injection of pituitrin 5U subcutaneous, once / d, or urine Disruption 0.3ml, 1 time / d, intramuscular injection, urine collapse light usually first given hydrochlorothiazide (hydrochlorothiazide), carbamazepine oral treatment, severe cases can be applied short-acting vasopressin, during which attention should be paid to control the amount of fluid To prevent water poisoning (at this time the patient may have edema, convulsions, etc.).
(2) Regularly measure the serum sodium, potassium, chlorine, carbon dioxide binding rate, and pH and blood urea nitrogen. The electrolyte is measured every 12 hours after 3 to 5 days after surgery. If the electrolyte is lost, it can be supplemented normally; Retention (increased blood sodium and increased osmotic pressure) should limit sodium intake; patients with low sodium and low chlorine should be supplemented with sodium chloride to prevent brain edema; to prevent hypokalemia from oral potassium chloride, 1000ml of chlorination Potassium 1g, in addition, must maintain potassium, calcium, sugar at normal levels.
4. Circulatory failure: preoperative patients with obvious pituitary dysfunction, prone to acute adrenal cortical failure after surgery, the patient is in a state of shock, the treatment is to add hormones before surgery, postoperative failure to give high-dose adrenal cortex Hormone, which not only reduces the crisis, but also reduces hypothalamic response and cerebral edema. It also has a positive effect on the prevention of central hyperthermia, but in order to reduce complications such as infection and gastrointestinal bleeding, it should be gradually reduced 4 days after surgery. Reduce the dosage, generally use the maintenance amount to stop gradually after 2 weeks (except for those with obvious pituitary dysfunction).
5. Epilepsy: Due to surgical trauma and hypothalamic traction, epilepsy occurs after anesthesia is awake, oral phenytoin sodium 0.1g, 3 times / d before surgery; intramuscular injection of 10mg or phenobarbital 0.1g To prevent, postoperative monitoring of EEG or observation of patients with or without sacral twitching, eyelid tremor, finger twitching and other signs, found that the abnormal drug is administered immediately before convulsion, repeated medication during seizures, while keeping the airway unobstructed, giving oxygen inhalation to prevent Brain tissue is hypoxic.
6. Gastrointestinal hemorrhage: After the subthalamic damage, the reflex caused gastric mucosal erosion, the ulcer caused by upper gastrointestinal bleeding and a large number of corticosteroids, the patient may have melena, hematemesis, and even acute gastric perforation.
Postoperative application of cimetidine, strict observation of blood pressure, pulse and stool color, indwelling gastric tube, observe the digestion of food in the stomach and the color of gastric juice, sudden hematemesis, melena, pulse rate, blood transfusion, ice brine wash Stomach, stomach injection of 1000IU thrombin, once / 4h, and the application of omeprazole, cimetidine, etc., blood transfusion, application of hemostatic agents, H2 receptor blockers, and fasting, gastrointestinal decompression , stop hormones, etc., if necessary, surgical treatment, so that bleeding is controlled in a timely manner.
7. Aseptic meningitis: The tumor capsule contents are caused by spilling and stimulating the meninges during surgery. For this reason, the tumor should be removed as much as possible during the operation, and the cysts should be repeatedly washed with saline. Emission of cerebrospinal fluid, the application of hormones can also help relieve symptoms such as fever.
8. Visual impairment: The intraoperative injury visual path and the blood vessels it supplies can cause visual impairment, especially the incidence of anterior-posterior type tumors should be noted.
9. Pituitary dysfunction: In particular, there are pituitary dysfunction before surgery, generally difficult to recover, children with growth retardation, short stature, sexual dysplasia, etc., treatment of thyroid hormones and other drugs and strengthen exercise, is expected to have some degree Recovery, but little grasp.
10. Others: Complications of intracavitary radionuclide internal irradiation in craniopharyngioma, each report can be combined: injury optic nerve crossing, optic tract, hypothalamus, radiation brain tissue necrosis, vascular embolization, and radiotherapy-induced tumor Etc. Very few tumors recur or die.
Symptom
Symptoms of pediatric craniopharyngioma Common symptoms Growth slow urineocytosis Increased intracranial pressure Secondary optic nerve atrophy Visual impairment Visual field defect Cachexia Concentric obesity Drowsiness Vision Concentricity
1. Increased intracranial pressure: Due to obstructive hydrocephalus caused by tumor obstruction of interventricular pores, the occupying effect of giant tumor itself is also one of the causes of increased intracranial pressure. 70.5% of patients with symptoms of intracranial hypertension , manifested as headache, vomiting, optic disc edema or secondary optic atrophy.
2. Endocrine dysfunction: The growth hormone, thyroid stimulating hormone, adrenocorticotropic hormone and gonadotropin secreted by the pituitary gland are obviously reduced, which is characterized by growth retardation, dry skin and secondary sexual development. As shown in Figure 1, due to pressure, the hypothalamus may have lethargy, diabetes insipidus, fat metabolism disorder (mostly centripetal obesity, a few cases of high malnutrition and cachexia), thermoregulatory disorders (more body temperature than normal), etc. .
3. Visual field of vision disorder: Almost all children with craniopharyngioma have visual impairment. The tumor optic chiasm can have primary optic nerve atrophy and bilateral hemianopia; when intracranial pressure increases, optic disc edema can occur, and optic nerve can be seen in the late stage. Secondary atrophy, visual field narrowing, a small number of tumors developed in the front cranial fossa and Foster-Kennedy syndrome.
Examine
Examination of pediatric craniopharyngioma
Ordinary laboratory tests are not special, endocrine function tests in most patients may have a low or flat delay in glucose tolerance curve, blood T3, T4, FSH, LH, GH and other hormones decreased, a few manifestations of hyperpituitarism, most performance The dysfunction of the pituitary gland and the corresponding target gland are not equal.
1. Growth hormone (GH) measurement and GH stimulation test Children with craniopharyngioma have lower serum GH value, and have no significant increase in insulin hypoglycemia, arginine, levodopa and other excitatory tests, accounting for 66.7%.
2. Gonadotropin (GnH) urinary gonadotropin (FSH), luteinizing hormone (LH) and GnH stimulation test, serum FSH, LH levels in patients with craniopharyngioma, and gonadotropin-releasing hormone (usually used For the LH-RH) stimulation test, there was no significant increase in response, suggesting that the tumor invaded the hypothalamic-pituitary region.
3. Prolactin (PRL) determination of patients with serum PRL levels can be increased, this may be due to tumor blocking prolactin release inhibitory hormone (PIH) into the pituitary, resulting in increased secretion and release of PRL, can cause galactorrhea, amenorrhea, accounting for 50%.
4. Adrenal cortex hormone ACTH, thyroid stimulating hormone TSH determination When the tumor is severely compressed by pituitary tissue and atrophy, the patient's serum ACTH, TSH decreased.
5. Antidiuretic hormone (ADH) determination of serum ADH in patients with craniopharyngioma often decreased.
6. Lumbar puncture has increased intracranial pressure, there may be increased lumbar puncture pressure, cerebrospinal fluid test no significant changes.
7. 80% to 90% of patients with skull X-ray plain film have abnormal changes in the X-ray film of the head. 94% of the children have abnormal changes in the flat film, and 60% of the adults. The main abnormalities are as follows.
(1) Tumor calcification: There are various forms of calcification of craniopharyngioma, which are prominent features of craniopharyngioma. Both saddle-type and saddle-type tumors have calcification, while other saddle lesions rarely have calcification (the incidence of calcification). More than 1%), calcification is more common in children than in adults, the incidence of calcification in children with craniopharyngioma is 70% to 85%, 20% in children under 2 years old, 80% in children over 2 years old, 15 years old 50% of the above, about 35% of adults, when children in the calcification of the saddle, should be considered as a craniopharyngioma, calcification can be large or small, can be dispersed, can also be concentrated together, sometimes can be curved thin line Calcification often occurs in the midline area. Occasionally, larger lesions can be limited to the surrounding part of calcification. 60% to 81% of patients have tumor calcification spots, which are single or scattered, and can also be fused into eggshell.
(2) Sella change: Children with TSH and GH deficiency, bone X-ray film can show bone age reduction, the vast majority of craniopharyngioma is located in the upper part of the sella, can press the saddle down, so on the skull flat It can be found that the sella is flattened and the bed is damaged. A few craniopharyngioma are located in the saddle. The sella can be seen on the flat slice. In fact, any type of sella can be seen in the craniopharyngioma. It can be typical. The tumor on the saddle can also be changed in the saddle. In 35% of the patients, the saddle is enlarged or destroyed by a basin or a sphere. The posterior bed and saddle can be sharpened, decalcified, disappeared, and the saddle has obvious changes. Often, there are huge lesions, and vice versa.
(3) Signs of increased intracranial pressure: 60% of patients showed signs of increased intracranial pressure on the X-ray film of the skull, which showed decalcification of the saddle back, obvious cerebral gyrus in the skull, and equal manifestation of the skull base. There are skull joints and so on.
8. CT scan of the brain showed a tumor change in the sellar region. The non-enhanced scan showed a high-density or iso-density image of the tumor, and the calcification was high-density. The cystic person showed a low-density image due to the cholesterol contained in the tumor. The CT value is -40 ~ 10Hu, the wall of the capsule is of equal density, the lesion boundary is clear, round, oval or lobulated, and the lateral ventricles are enlarged on both sides. About 2/3 of the cases in the enhanced scan may be different. The degree of enhancement, CT value increased by 12 ~ 14Hu, cystic craniopharyngioma showed ring enhancement or multi-ring enhancement and no enhancement in the central low-density area, a few craniopharyngioma were not strengthened, generally with calcification, cystic cavity and strengthening After the enhancement of the three manifestations of the sellar tumor, the diagnosis of craniopharyngioma can be confirmed.
9.MRI Most of the cystic parts of craniopharyngioma contain short T1 and long T2, but can also be long T1 and long T2 images, ie, low signal on T1 weighted image and high signal on T2 weighted image; If it is a solid craniopharyngioma, it has a long T1 and a long T2, and the calcification plaque is a low signal region.
CT and MRI examinations are important for diagnosis. These two examinations can show the location and size of the tumor, the presence or absence of cystic changes, the invasion of the tumor to adjacent brain tissue, and the presence of hydrocephalus. In general, MRI is on display. The structure of the tumor and its relationship to adjacent brain tissue (such as optic chiasm) take precedence over CT, but he cannot show calcifications like CT.
10. Because cerebral ventriculography varies in tumor size, ventriculography can clearly show the influence and change of tumor on the skull base artery. It is very helpful for surgery. Whether the tumor cyst is connected with the ventricle can be directly puncture at the same time as ventriculography. Into the tumor cyst.
11. The EEG is dominated by the forehead or a wide range of delta or theta waves.
Diagnosis
Diagnosis and diagnosis of pediatric craniopharyngioma
diagnosis
The diagnosis of pediatric craniopharyngioma is not difficult, and its characteristics are:
1. Increased intracranial pressure Most children have increased intracranial pressure.
2. Growth arrests growth stagnation and secondary sexual characteristics are not developed.
3. Tumors located in the sellar region are located in the saddle area and are more common in cystic and calcification.
4. Visual impairment The visual loss is more prominent than the visual field defect.
Differential diagnosis
1. The incidence of saddle-top germ cell tumors is low. The first symptoms are almost polydipsia and polyuria. The calcification sac becomes rare, the optic nerve is mostly atrophied, the hemiplegic hemiansis is more, and the intracranial pressure is less.
2. Optic glioma unilateral painless and non-pulsating exophthalmos are more common, vision loss is mostly the first symptom, X-ray plain film can be seen enlarged optic nerve hole, calcification is rare.
