Schwannoma

Introduction to schwannomas Neurilemmoma (neurilemmoma), also known as schwanncelltumor or Schwannoma, usually a single schwannomas, derived from the nerve sheath, head and neck schwannomas mainly occur in the cranial nerve, such as The auditory nerve, facial nerve, hypoglossal nerve, vagus nerve; secondly, it can occur in the head and face, the peripheral nerve of the tongue, the most common in the sympathetic nerve, the clinical manifestation of solid nodules with tenderness, slow growth of the tumor, the course of disease long. Surgical resection is the main treatment for this disease. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: cerebrospinal fluid leakage facial nerve injury glioma cell ataxia

The cause of schwannomas

(1) Causes of the disease

Schwannomas originated from Schwann cells. Although there are some speculations about the etiology of neuroma, the true predisposing factors have not been fully discovered until now. The most popular reason is that the tumor suppressor gene is missing.

(two) pathogenesis

The tumor has a complete capsule, the cut surface can be reddish, gray or yellow, and sometimes the cyst formed by degeneration can be seen, containing bloody liquid. Under the microscope, the tumor parenchyma is mainly composed of nerve sheath cells, and occasionally mature ganglion cells and The involvement of neural stems can be divided into two types: dense type and mesh type according to the characteristics of tissue structure.

1. Compact type (Antoni type A) has the following characteristics: Schwann cells are usually arranged in a sinus shape or a bundle, with fine connective tissue fibers; the nucleus tends to be arranged in a fence shape and is in phase with the non-nuclear region.

2, mesh type (Antoni B type) Schwann cells arranged evacuation disorder, interstitial edema, visible mucus degeneration of the matrix to form a plurality of small cysts, small cysts can fuse with each other to form a large cyst, the cavity is filled with liquid, visible in the tumor Many hypertrophic cells, the tumor is rich in blood vessels, especially the loose reticular area, the blood vessel wall is thin, accompanied by thrombosis and bleeding.

Schwannomas prevention

1. Preventive measures :

No special effective precautions.

2, malignant tumor prevention .

Primary prevention is to reduce or eliminate the carcinogenic effects of various carcinogenic factors on the human body and reduce the incidence rate. For example, you should pay attention to participate in physical exercise, change your own low mood, maintain strong energy, and improve your immune function and disease resistance. Pay attention to diet, drinking water, prevent cancer from entering the mouth; do not eat mildew and spoilage, burnt food and smoked, grilled, marinated, soaked food, or do not drink for a long time to store water, no smoking, no alcohol, Scientifically match the diet, eat more fresh vegetables, fruits and nutritious foods, develop good hygiene habits, and at the same time pay attention to protect the environment, avoid and reduce pollution to the atmosphere, diet, drinking water, can prevent physical, chemical and parasites , cancer and other carcinogens on the human body, effectively prevent the occurrence of cancer.

Secondary prevention is an effective means of early detection, early diagnosis and early treatment to reduce the death of cancer patients. In addition to strengthening physical exercise, we should pay attention to some physical changes and regular physical examinations, such as taking pictures of chest radiographs and bronchoscopes. Examination can find early lung cancer; B-mode ultrasound scan, alpha-fetoprotein determination can reveal liver cancer; routine vaginal cytology examination, early detection of cervical cancer; esophageal pull net examination, fiber esophagoscopy, gastroscopy, colonoscopy, Early detection of esophageal cancer, stomach cancer, colon cancer, etc., therefore, once the body is found to have cancer, must go to the oncology hospital to diagnose and treat, establish confidence in the fight against cancer, and actively cooperate, cancer can be cured.

Tertiary prevention is to prevent cancer recurrence and metastasis, prevent complications and sequelae when treating cancer. At present, oncology hospitals have the advantage of a comprehensive treatment, and different treatment methods for different tumor diseases, such as surgery. Resection of tumors, chemotherapy, radiotherapy, Chinese medicine, immunization and other treatments, I believe that as long as you pay attention to learning, master the common and basic knowledge of cancer prevention and treatment, everyone can capture the signs and manifestations of certain cancers as soon as possible, so as to promptly see a doctor and assist doctors to do so. Timely diagnosis and timely treatment.

Schwannoma complications Complications Cerebrospinal fluid leakage facial nerve injury Glioblastoma ataxia

Complications usually occur in surgery.

1, complications during surgery: 1 bleeding; 2 acute brain stem infarction and mechanical injury, severe intraoperative death.

2, early postoperative complications: 1 postoperative bleeding, (pre-cranial preemptive Kyushi test prevention); 2 brain stem or cerebellar edema, intracranial hypertension.

3, postoperative complications: 1 cerebrospinal fluid leakage (in the operation with bone wax to seal the mastoid and the fracture of the rock cone can be prevented); 2 cranial nerve palsy, usually facial nerve injury, can also have three nerves, Glossopharyngeal nerve, vagus nerve injury; 3 brain symptoms: ataxia, difficulty in pronunciation; 1 pyramidal beam damage: manifested as limb dyskinesia.

4, postoperative complications: 1 intracranial infection; 2 cerebrospinal fluid circulation disorder; 3 tumor recurrence, partial tumor resection, the recurrence rate is 80%, the recurrence time is one to several years after surgery, recently knife successfully For the treatment of acoustic neuroma, the tumor can be significantly reduced, early tumor growth can inhibit tumor growth, and nerve function can be selectively used in some cases.

Schwannomas occur in many other organs and can cause brain tumors such as meningiomas, gliomas, and astrocytoma.

Symptoms of schwannomas Common symptoms Facial muscle twitching Single solid nodule Motor dysfunction Sound hoarseness dysfunction

Occurs in the limbs, especially the lower limbs, but also in the head, neck, face, stomach, posterior and posterior mediastinum, intracranial, spinal canal is not uncommon.

Slow-growing, painless mass, round or oval, tough texture. If it is too large, it can be cystic due to liquefaction in the tumor. It can also puncture a reddish-brown liquid. The tumor can follow the nerve axis. Swing can not move up and down, from the sensory nerve can have tenderness and radiation pain; from the facial nerve will appear facial muscle twitch; from the vagus nerve can have hoarseness; from the sympathetic nerve can appear Horner (Horner synthesis) Symptoms, etc.

1, solid nodules

Single or multiple solid nodules in the dermis or subcutaneous tissue, round or oval, usually no more than 2 to 4 cm in diameter, can be pushed (Fig. 1), soft or solid, pink or light yellow, may have Or no pain, occasional damage is multiple, can be seen in type I neurofibromatosis or independent, and has no relationship with type I neurofibromatosis, but multiple lesions are often associated with type II neurofibromatosis, independent type can be Congenital or delayed, can be sporadic or familial, clinically manifested in three appearances, that is, high dome-shaped nodules, light brown induration rash and multiple papules merge into 2 ~ 100mm plaque .

Plexus schwannomas can be single or multiple lesions, localized or generalized, occurring in the dermis or subcutaneous tissue, either alone or with type I, type II neurofibromatosis or multiple Schwannoma is associated with another type of schwannomas. The squamous pigmentation of the sand-like tumor type and Carney syndrome, accompanied by excessive myxoma and endocrine activity, can occur in malignant subtypes, and type I neurofibroma. Single lesion associated with the disease, or in some cases associated with pigmented dry skin disease.

2, sour feeling

Generally, there are no symptoms, but there is a feeling of numbness in the touch. When the volume is increased, it is often accompanied by radiation-like pain.

3, feeling and movement disorders

If the tumor significantly compresses the nerve, sensation and movement disorders may occur.

According to the clinical manifestations, the characteristics of skin lesions, histopathological characteristic immunohistochemistry can be diagnosed, the disease is difficult to make a diagnosis clinically, and a biopsy is needed for the diagnosis.

Schwannoma examination

1, for the clinical performance is more typical, preoperative diagnosis has been more clear, check the project to check the box limit "A".

2, for the clinical manifestations are atypical, the differential diagnosis is more difficult, the larger the tumor is closely related to the surrounding important structure or suspected of malignant examinations can include the inspection box "B" and "C".

Immunohistochemical S-100 protein, corrugated fibrin and myelin base protein staining positive.

Histopathological examination : the naked eye of the tumor is fusiform or spherical, the surface is smooth, the capsule is intact, the cut surface is grayish white, yellowish brown, homogeneous, translucent; under the microscope, Schwann cells are bundled or evacuated, and there may be There are many lobular or vortex-like structures, and there are many cases of hemorrhage, necrosis, and cystic changes. The larger the tumor is more likely to occur. The Antoni type is composed of cells with elongated and deeply stained cells. In most areas, The nucleus is arranged in a wave shape in a spiral shape. In addition, a highly characteristic arrangement can be seen, that is, two columns arranged in parallel, surrounded by a substantially nuclear-free homogeneous substance, which is called Verocay body. Diagnostic value, Antoni B type tissue consists of edema interstitial, which contains a very small number of cells, the nucleus of different forms, nerve staining with Bodian staining, only a few or no nerve fibers, which is different from neurofibroma, But like neurofibromatosis, many mast cells are also seen.

Diagnosis and diagnosis of schwannomas

Diagnosis can be based on medical history, clinical symptoms, and laboratory findings.

Differential diagnosis

1. Early vertigo in acoustic neuroma should be differentiated from vertigo in the inner ear, vestibular neuronitis, labyrinthitis and various drug-induced vestibular nerve damage. The former has progressive deafness with facial nerve dysfunction.

2, deafness should be distinguished from inner ear sclerosis, drug-induced deafness, acoustic neuroma has vestibular dysfunction.

3. Identification with other tumors of the cerebellopontine angle:

1 Epidermoid cyst: the first symptom is mostly trigeminal nerve root irritation, the hearing loss is not obvious, the vestibular function is mostly normal, CT, MRI can help identify.

2 Meningioma: Tinnitus and hearing loss are not obvious, the inner ear canal does not expand, 10% occurs in the saddle, the flat scan is evenly high density, there may be calcification, the cystic change is rare, and the tumor is usually in the position of the saddle. Saddle nodule bone hyperplasia.

3 brain stem or cerebellar hemisphere glioma: short course of disease, brain stem or cerebellar symptoms appear earlier, early appearance of pyramidal tract signs.

4 metastasis, acute onset, short course of disease, other parts may find primary cancer.

4 astrocytoma: astrocytoma above the third ventricle often appears as a solid mass on the saddle, generally does not extend into the saddle, the calcification rate is lower than that of the craniopharyngioma, but with the parenchyma of the saddle It is sometimes difficult to give a tumor.

5 aneurysm: There may be calcification on the wall of the giant aneurysm, and the wall of the tumor is strengthened by the organic tissue during the scanning. However, the strengthening of the blood in the aneurysm is very significant, consistent with the enhancement of the intracranial artery, and occasionally strengthen the uniform artery. It is difficult to distinguish from parenchymal craniopharyngioma. It is necessary to carefully analyze the relationship between the tumor and the blood vessels of the cerebral artery. If it cannot be distinguished, MR examination or cerebral angiography should be performed.

4. The histopathology of neurofibromatosis neurofibroma has the following characteristics:

(1) It is tough, elastic and non-enveloped.

(2) Tumor cell evacuation, occasional fence or spiral structure.

(3) The god of origin in the tumor is often interspersed with it.

(4) sweat glands and adipose tissue are often seen in the tumor, and there are no thick-walled blood vessels.

(5) Alcian blue staining positive.

5, malignant schwannomas and cell-rich schwannomas should pay attention to identification, the former capsule is incomplete, tumor tissue often accompanied by necrosis, often infiltration into the surrounding tissue; nucleus is polymorphic, with obvious abnormal shape, visible Giant tumor cells, mitotic figures are easy to see.

6, sclerosing schwannomas like leiomyomas or fibroids, but a number of sections can always find a typical structure of schwannomas, cell characteristics and V, G, staining can help identify.

7, the pain should be differentiated from glomus tumors.

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