Orbital neurofibromas

Introduction to orbital neurofibroma Neurofibroma is also a benign tumor of the peripheral nerve. Unlike schwannomas, it is caused by the proliferation of neurofibroblasts in the pathological tissues in addition to the proliferation of nerve sheath cells. Clinical manifestations are also more diverse than schwannomas. basic knowledge The proportion of illness: 0.0015% Susceptible people: no special people Mode of infection: non-infectious Complications: neurofibromatosis

Cause of orbital neurofibromatosis

(1) Causes of the disease

The cause is currently unclear.

(two) pathogenesis

The pathogenesis is still unknown.

There are three types of orbital neurofibromatosis, which are localized, plexiform, and diffuse. They can be seen alone in the eyelids, but they can also be used as part of neurofibromatosis. They cut off postoperative neuroma (representing massive excessive growth of the peripheral nerve after cutting). However, eyelids are extremely rare. The plexus plexus neurofibroma with neurofibromatosis is more common.

Orbital neurofibroma prevention

The cause is unknown, and there is currently no effective preventive measures, timely detection and surgical treatment, so as not to cause further damage is very important. Take care to minimize infection and avoid exposure to radiation and other toxic substances, especially drugs that have an inhibitory effect on immune function; active virus and certain physical properties (such as radiation), chemistry (such as anti-epileptic drugs, adrenocortical hormones) Long-term application of the substance.

Orbital neurofibromatosis complications Complications neurofibromatosis

Neurofibromatosis can also be found in other parts of the body such as skin, subcutaneous tissue, bones, and internal organs.

Symptoms of orbital neurofibromatosis Common symptoms Horner's syndrome, hyperemia, double eyeball, upper eyelid, drooping, eversion

Most of the limitations occur in young and middle-aged people. There is no difference in the prevalence of males and females. Most of them occur in one eyelid. The symptoms and signs are similar to those of schwannomas. Those who occur in the deep part of the sputum cause chronic progressive vision loss and prominent eyeballs. And double vision, tumors caused by sensory nerves, patients can feel abnormal, slow or lost, from motor nerves, early appearance of ocular dyskinesia, anterior iliac crest and mass, clear boundary, can promote, more benign tumors Hard, Krohel et al reported that 12% of localized neurofibromas were associated with neurofibromatosis.

Most of the orbital plexus neurofibroma is the ocular manifestation of neurofibromatosis. Only a few cases lack other parts of the disease. This type of age is different from the limitations. Symptoms and signs appear after birth or at an early age. Including the eyelids, the soft tissue of the iliac crest, the tibia and the adjacent brain, the ankle, etc., the earliest and most common eye, the lower jaw soft hypertrophy, the subcutaneous tumor tissue hyperplasia, the upper and lower iliac bulge, the eyelid skin is often light Brown pigmentation spots, the eyeballs protrude forward and downward, although the eyeballs are prominent, but it is not difficult to incorporate them into the sputum. The tumor tissue can directly invade various structures in the iliac crest, and the levator levator is firstly affected, causing The sag is drooping, the lifting is insufficient or impossible, and some cases only retain the function of the medial part of the levator palpebral muscle. The extraocular muscle invasion causes the ocular dyskinesia, the early onset is insufficient, the optic nerve is invaded to cause vision loss, and the orbital lesion often involves the upper eyelid. Plate, starting on the outside, nodular swelling, causing valgus eversion, conjunctival hyperemia, hypertrophy, subcutaneous tumor growth, eyelid skin hypertrophy can be bag-like, sagging On the cheeks, a so-called horse-like neurofibromatosis is formed, the eye is percussed, the subcutaneous can touch the strip, the nodular or diffuse soft mass, the boundary is absent, the tibial bone is missing, and the anterior Irregular depression; occurs in the posterior part of the sacral posterior meningeal bulge, can cause pulsatile ocular bulging, deep sputum and pulsatile mass, bulging meningeal brain tissue, eyelids, orbital tumor It often spreads to the ankle and face, showing swelling of the ankle, subcutaneous soft mass and bone loss, facial swelling, sagging, ipsilateral nasal sag, pulsatile eyeball, soft skin of the trunk and brown pigmentation.

Diffuse neurofibroma is mainly found in the skin. It is rare in the sputum, such as tumor invasion of subcutaneous tissue, intraorbital fat, extraocular muscles and other soft tissues, thick eyelids, eyeball protrusion and limited eye movement, clinical manifestations and plexus Neurofibromatosis is similar.

Examination of orbital neurofibroma

Pathological examination: Different types of pathological changes are different. Localized orbital neurofibroma is a round or irregular mass, grayish white or pinkish white, lacking envelope, clear boundary It is solid, hard, and can also be seen in the cystic zone. It is often found that the tumor has a nerve bundle at one or one side of the tumor. Under low magnification, the fusiform tumor cells and the collagen fiber bundle are arranged in a wavy or swirling shape. Separated by mucopolysaccharide groups, spindle-shaped neurofibrillary fibroblasts and nerve sheath cells can be separated under high magnification; the latter nucleus is comma-like, and occasionally the tumor nucleus is arranged in a fence, similar to schwannomas.

The appearance of plexiform neurofibroma specimens is different from that of localized neurofibromatosis. The tumor is seen as a soft proliferative mass in the naked eye, which lacks a clear boundary with normal tissue structure. Muscle tissue, lacrimal gland tissue and optic nerve sheath, especially The levator numbness is often violated. The soft mass contains white granular or stripy tumor tissue. The enlarged nerve bundle extends a few centimeters to the deep of the eyelid, the ankle or cheek. Under the microscope: there is a sheath nerve in the tumor. Fibrous and non-sheathed fiber axons, fibroblasts and collagen fibers are bundled loosely within the mucin-like matrix, and the tumor has brown pigmented spots adjacent to the skin. Under the microscope, the pigment is located in the basal cell layer of the epidermis, and diffuse neurofibroma (diffuse neurofibroma) has the same cellular components as the upper two types. The tumor cells spread across the perivascular membrane, spread along the connective tissue septum and intercellular space, do not destroy the supporting tissues of the nerve, and special staining and immunohistochemical tests are helpful for diagnosis. The mucin-like matrix Alcian blue and other acid mucopolysaccharide staining between tumor cells were positive, and Bodian staining observed nerves. The cell axon, S-100 protein is positive, indicating that it is a tumor derived from neural crest, which is meaningful for diagnosis.

1. X-ray examination of isolated or localized neurofibromas can cause eyelid enlargement, the most obvious incidence in infants and young children, increased density of the sacral cavity, thinning of the sacral wall, sclerosis, plexiform neurofibroma can also cause sacral cavity Enlargement, thinning of the sacral margin, hardening, often accompanied by large sphenoid bones, lack of part of the winglets and frontal humerus, manifested as "empty levy", the expansion of the upper and lower diameter of the eyelids as "implantation sign", the above two signs The so-called specific signs of neurofibromatosis, adjacent to the frontal bone, humerus or parietal bone can also have a wide range of bone defects, X-ray film can also show the expansion of the optic nerve.

2. B-ultrasound analysis of isolated or localized neurofibromatosis showed single-occupied space-occupying lesions, which were round or irregular, with clear boundaries but not smooth, less internal echoes and mainly distributed in the front of the tumor. The sound attenuation is more obvious, and sometimes it is even difficult to show the posterior boundary of the tumor. The plexiform neurofibroma appears as a multi-echoic lesion with unclear boundaries. It is more common with strip echo or less echo. CDI shows that the blood flow in the tumor is rich, and For the arterial spectrum.

3. CT scan of isolated or localized neurofibromatosis is limited, the boundary is clear soft tissue mass shadow, round or oval, uniform density, similar to brain parenchyma, can oppress adjacent wall, bone thinning, different Degree hardening, most tumors are evenly enhanced after enhancement, a few tumors are unevenly enhanced, plexiform and diffuse neurofibromas show markedly enhanced soft tissue shadows, irregular contours, invasive growth appearance, lesions can extend to all adjacent sputum Structures, such as lacrimal glands, fat and extraocular muscles, on plexiform neurofibroma, mainly involving the eyelids, often extending to adjacent areas, such as the armpits, forehead, etc., when evaluating CT scans of plexiform neurofibroma, Other signs consistent with the diagnosis of neurofibromatosis should be observed, such as the absence of sphenoid wings and domes, the lesions on the side of the lesion may increase, and even the entire uvea may be involved.

4. MRI isolated or localized neurofibroma T1WI is a medium signal, T2WI is a high signal, the boundary is clear, oval or fusiform, most of the internal signals of the tumor are more uniform, and a few tumors exist due to mucus matrix and cystic components. The display signal is not uniform, and the light is moderately enhanced after enhancement. The plexus and diffuse neurofibroma are characterized by unclear lumps of the orbital boundary, extending extensively to the axilla, frontal and other adjacent structures, and the sputum can also show scattered. Nodular soft tissue shadows, sometimes lesions spread through the supracondylar fissure, lesions showed a non-uniform low signal on T1WI, high signal on T2WI, enhanced contrast showed different degrees of enhancement, enhanced scan combined with fat suppression technology showed the best .

Diagnosis and diagnosis of orbital neurofibromatosis

X-ray film has certain value for this disease, especially showing that patients with neurofibromatosis can clearly show the "empty sign". B-ultrasound is of little value to the disease and can show large lesions in the sputum. However, it is difficult to qualitatively diagnose, and it is difficult to show the extent of the lesion. CT can clearly show the lesion, especially for the temporal wall and adjacent bone, but it is difficult to accurately show the relationship between the lesion and the optic nerve and extraocular muscle, and it is difficult to display the skull. Internal and external tumors, MRI can accurately show the extent of the lesion, especially showing the relationship between the lesion and the adjacent structure, but also clearly show the tumors associated with other sites, but it is difficult to clearly show the bone wall changes, isolated neurofibroma MRI diagnosis is the main, plexiform neurofibroma is mainly diagnosed by CT, and the method of examination for neurofibromatosis includes X-ray film, CT and MRI.

Imaging can be used to identify schwannomas and cavernous hemangioma.

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