Craniopharyngioma Craniopharyngioma is a benign congenital tumor that occurs from the remnant tissue of the craniopharyngeal duct during embryonic period, accounting for about 4% of intracranial tumors; however, it is the most common congenital tumor in children, accounting for the first place of saddle area tumors.
Pathology
Generally speaking, the surface of tumor is smooth or nodular, with envelope and clear boundary. The contents of cystic tumor are mostly necrotic and liquefied epithelial debris, containing a large amount of cholesterol crystals, which are green liquid-like, sometimes thick like organic oil. The tumor histology can be divided into enamel epithelial type and squamous epithelial type, almost all of which are the former in pediatric patients, while each type accounts for half of the adult patients. Based on the relationship between craniopharyngioma and saddle diaphragm, ventricles, etc., craniopharyngioma is categorized as
Grade I: the tumor is located completely in the saddle or below the saddle diaphragm.
Grade II: tumor located in the suprasellar pool with or without tumor in the saddle
Grade III: tumor invades the lower part of the third ventricle
Grade IV: tumor invades the superior half of the third ventricle.
Grade V: the top of the tumor reaches the hyaline septum or enters the lateral ventricle.
Clinical manifestations
Craniopharyngioma grows slowly and causes a series of neurological and endocrine symptoms and signs due to its location and development direction, among which visual dysfunction is the most common.
1. Symptoms of hypothalamic-pituitary axis damage may include hypothermia, lethargy, uremia, and obesity reproductive incompetence syndrome. Tumor compression of anterior pituitary tissue causes hypopituitarism, which leads to insufficient secretion of growth hormone and gonadotropin and growth disorders, delayed or even stopped skeletal growth, and often impaired development of sexual organs and no secondary sexual characteristics by puberty. It can be manifested as short stature, although it has reached adulthood, the body shape is still like a child, called growth hormone deficiency dwarfism (also known as pituitary dwarfism); there are also general weakness and lethargy, little movement, loss of appetite, loss of libido, pale and delicate skin, low basal metabolic rate and other manifestations; male impotence, female menstrual disorders or menopause.
2, visual function and other brain nerve dysfunction tumor growth to the saddle often directly compress the optic nerve, optic cross and optic tract.
3, symptoms of increased cranial pressure, headache, nausea and vomiting, optic disc edema and spreading nerve palsy, etc. Advanced patients may appear drowsiness or even coma.
Auxiliary examinations
1.Imaging examination
(1) Cephalometric X-ray plain film.
(2) Cranial CT scan: cystic craniopharyngioma can be shown as a low-density shadow in the suprasellar region with clear borders, round, oval or lobulated on CT. CT scan of parenchymal tumor shows uniform hyperdensity shadow and scattered dotted calcification shadow; eggshell-like calcification shadow of cystic tumor cyst wall is one of the main bases for the diagnosis of cystic craniopharyngioma.
(3) Cranial MRIMRI shows tumor morphology, growth direction and its relationship with surrounding adjacent area more clearly, but it is not good for showing calcification and bone destruction.
(2) Endocrinological examination is performed to determine the function of pituitary gland and its related target glands before surgery, and most cases have different degrees and types of hypopituitarism of target gland axis.
3.Visual function examination includes visual field examination and fundus examination.
[Diagnosis and differential diagnosis
The diagnosis of pediatric craniopharyngioma is relatively easy, and can be confirmed when the saddle area is found to be occupied with signs and symptoms such as enuresis, growth retardation, general weakness, visual field changes, and increased intracranial pressure. The diagnosis of adult patients is sometimes more difficult because most craniopharyngiomas in adults are substantial and require surgical removal of pathological tissues to confirm the diagnosis.
Treatment
For cases with small invasion or invasion limited to the funnel and gray nodes at the base of the third ventricle, microsurgery should be preferred for total removal of craniopharyngioma, which has a higher cure rate. When the tumor is large and closely adheres to the internal carotid artery, optic nerve, pituitary stalk, hypothalamus and other surrounding tissues, even if it is barely removed, the result may not be satisfactory, and even serious complications of irreversible damage at the level of optic pathway-mesencephalon-frontal lobe may occur, which may endanger life. For cases with severe hypothalamic symptoms, already impaired consciousness, bedridden and preoperatively estimated to be unable to tolerate craniotomy, more conservative treatment methods can be chosen. For craniopharyngioma in grade III, IV, and V, transfrontal inferior approach, pterygoid point approach, endplate approach, transcallosal or transcortical lateral ventricular approach, and combined approach can be considered. Avoiding damage to the hypothalamus during surgery is the key to successful surgery.
2.Radiation therapy uses fractionated general radiation therapy or stereotactic radiosurgery according to the condition. Radiation therapy can increase the survival time and delay the tumor recurrence.