intracranial chordoma
Introduction
Introduction to intracranial chordoma Chordoma is a destructive tumor rarely seen in the brain. It is deep in the base of the skull. The clinical diagnosis is mainly based on neurological symptoms and typical imaging changes. The intracranial chordoma is mostly from the midline of the slope. Outside the membrane, it grows slowly and infiltrates. basic knowledge The proportion of illness: 0.0005%-0.0008% Susceptible people: no special people Mode of infection: non-infectious Complications: hydrocephalus, dizziness, dysphagia, cerebrospinal fluid leakage, meningitis
Cause
Causes of intracranial chordoma
Normal type (25%):
Also known as the typical type, the most common, accounting for 80% to 85% of the total, no cartilage or other mesenchymal components in the tumor, more common in patients aged 40 to 50 years old, less than 20 years old, rare, no gender differences, pathologically Several growth modes, but characterized by flaky growth, consist of vacuolar epithelial cells and mucus matrix, immunostaining positive for cytokeratin and epithelial membrane antigen, and nuclear granules for electron microscopy. These characteristics contribute to the disease and cartilage. The sarcoma is different, the latter is negative for immunostaining, and the electron microscope has no nucleus.
Cartilage-like chordoma (25%):
It accounts for 5% to 15% of chordoma, and its microscopic features, in addition to the above-mentioned typical findings, contain varying degrees of hyaline cartilage-like areas, although some authors classify them as low-grade chondrosarcoma by electron microscopy. However, a large number of immunohistochemical studies have found that the epithelial marker antigen of chondrogenic chordoma is positive, and the age of onset is mild. In the past, the prognosis was generally better than the common type. It is now considered that the prognosis is similar.
Interstitial type (20%):
Also known as atypical, accounting for 10% of chordoma, containing common components and malignant mesenchymal components, microscopically showed active tumor proliferation, significantly reduced mucus content and visible mitotic figures, a small number of tumors can be transferred by blood flow and Subarachnoid space implanted, this type can be secondary to ordinary radiotherapy or malignant transformation, often died 6 to 12 months after diagnosis.
Prevention
Intracranial chordoma prevention
There is no effective preventive measure for this disease. Early detection and early treatment are the key to the prevention and treatment of this disease.
Complication
Complications of intracranial chordoma Complications hydrocephalus vertigo dysphagia cerebrospinal fluid meningitis
Because the tumor occurs in the skull base, it can cause traffic hydrocephalus. If the tumor develops toward the cerebellopontine angle, hearing disorder, tinnitus and dizziness appear. The chordoma originates from the vicinity of the nasopharyngeal wall, often protruding into the nasopharynx or infiltration. Or more paranasal sinus, causing nasal insufficiency, obstruction, pain, common purulent or bloody nasal secretions, but also due to mechanical obstruction, causing difficulty in swallowing, nasopharyngeal symptoms often appear before nerve involvement, must be remembered In the nasopharyngeal cavity, there is a 13% to 33% chance of seeing a lump.
Surgical complications include cerebrospinal fluid leakage, meningitis and cranial nerve damage (most of which can be recovered).
Symptom
Symptoms of intracranial chordoma common symptoms growth slow dull pain optic atrophy intracranial pressure increased cranial nerve palsy hemianopia amenorrhea amenorrhea
Intracranial chordoma is a benign tumor with slow growth and a long course of disease, which can last for more than 3 years. Headache is the most common symptom. About 70% of patients have headaches, sometimes they have been headache for several years before going to the hospital. Headache can also be extended to the back of the occipital or neck. The nature of the headache is persistent and dull. There is no significant change in the day. If there is an increase in intracranial pressure, it will be aggravated. The headache of chordoma is related to the slow and persistent bone infiltration of the skull base. The headache can also be repeated.
The clinical manifestations of intracranial chordoma may vary depending on the location of the tumor and the direction of the tumor.
Saddle chordoma
Pituitary dysfunction is mainly manifested in impotence, amenorrhea, body fat, etc., optic nerve compression produces primary optic atrophy, vision loss and bilateral hemianopia.
2. Saddle chordoma
Mainly manifested in III, IV, VI cranial nerve palsy, which is more common in abduction, which may be because the nerve length is too long, in addition, the proximal end of the nerve is often the origin of the tumor, so that its incidence is higher Generally, it is slowly progressing slowly. Even after 1 to 2 years, cranial nerve palsy can be bilateral, but often unilateral. It is difficult to understand that it is often on the left side.
3. Slope chordoma
Mainly manifested as brain stem compression symptoms, namely walking disorders, pyramidal tract signs, VI, VII cranial nerve disorders, of which bilateral occlusion nerve damage is characterized.
Examine
Examination of intracranial chordoma
No special performance.
1. The skull X-ray film has important diagnostic significance, which is manifested as bone destruction in the site of the tumor, and is also common to plaque or lumps of tumor calcification.
2. CT scan showed a round or irregular slightly high density shadow at the base of the skull. The boundary was clear, there was calcification in the tumor, and the enhanced tumor was not strengthened or slightly strengthened. The bone window showed obvious bone destruction.
3. MRI tumors are mostly long T1 and long T2 signals. The intratumoral cystic zone has a longer T1 long T2 signal, calcification is black with no signal, and hemorrhagic lesions have a high signal. After injection of Gd-DTPA, the tumor is mild to moderate. strengthen.
4. Cerebral angiography, such as the tumor located in the saddle area, can be seen that the siphon segment of the internal carotid artery is moved outward, the horizontal section of the anterior cerebral artery is lifted, and the sinus of the internal carotid artery is elevated. The segment and the horizontal segment are also lifted up, and the tumor that develops to the posterior cranial fossa often pushes the basilar artery toward the posterior or posterior aspect.
Diagnosis
Diagnosis and diagnosis of intracranial chordoma
diagnosis
Adult patients with a history of long-term headaches, and one side of the nerve palsy, should consider the possibility of chordoma, but the diagnosis requires X-ray, CT and MRI imaging.
Differential diagnosis
Chordoma should be differentiated from meningioma. Meningioma in the same area can cause local bone compression or bone hyperplasia, but less osteolytic changes. DSA common meningeal blood supply artery thickening, obvious tumor staining.
For example, the growth of chordoma to the posterior fossa should be differentiated from the acoustic neuroma of the cerebellopontine angle. The acoustic neuroma is mainly characterized by the enlargement of the internal auditory canal and the absorption of the sacral iliac crest in the flat film and CT of the skull. MRI often contributes to the differential diagnosis. .
The chordoma in the saddle area needs to be differentiated from pituitary adenoma and craniopharyngioma. The latter two do not cause extensive destruction of the skull base. The pituitary tumor is generally characterized by enlarged saddle involvement and saddle bottom. Deepening, bone resorption, craniopharyngioma CT can be seen on the wall of the capsule with arc-like or egg-shell calcification, usually does not cause adjacent bone destruction, and both cranial nerve damage is mostly confined to the optic nerve, while chordoma is mostly Multi-brain nerve damage mainly based on augmentation of neurological disorders, radiographic osteolytic changes in the skull base and speckle-like or flaky calcification in the tumor.
The chordoma that grows down into the nasopharynx is similar to the nasopharyngeal carcinoma that is transferred to the skull base because of its clinical manifestations and X-ray examination. The differential diagnosis relies mainly on the biopsy of the nasopharynx.
It is difficult to identify chordoma of the parasagittal or long-middle-skull base with chondrosarcoma. Immunohistochemical staining is helpful. Chordoma is positive for various tissue markers, such as: Cyto-K6/7, EMA7/7 , CEA6/7, GFAP0/7, Des0/7, -AT7/7, Lyso4/7, and chondrosarcoma showed negative.
