Aneurysmal bone cyst

Introduction to aneurysmal bone cyst The disease is benign bone disease, the shape of the diseased vertebral body is cystic bulging, and the cyst cavity is filled with blood. Therefore, the disease is called arterial-like bone cyst, and its nature is unknown. Some people think that it is a benign tumor, and some people think that it is a tumor-like lesion. According to the literature, the entire spinal aneurysm-like bone cyst accounts for about 4% of spinal tumors, and the age of onset is mostly 10 to 20 years old. There is no difference between men and women. The etiology of this disease has not been known so far, it may be primary, or secondary or associated with giant cell tumor of bone, chondroblastoma or osteoblastoma, this disease occasionally has a malignant tendency. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific people Mode of infection: non-infectious Complications: spinal cord compression

The cause of aneurysmal bone cyst

Cause (30%):

The etiology of this disease has not been known so far, most scholars believe that it may be due to local persistent hemodynamic disorders, causing extreme elevation of venous pressure leading to vasodilation, resulting in the absorption of affected vertebral bone.

Pathogenesis (30%):

The pathogenesis of the disease is currently more controversial. Most scholars believe that the internal arteries and veins are abnormally anastomosed, resulting in increased internal pressure, enlarged blood vessels, bone destruction, and bloody cysts formed by hemorrhage. In recent years, many scholars have divided the disease. Both primary and secondary, the so-called primary refers to the presence of aneurysmal bone cysts, no other associated lesions are found, secondary refers to the disease often associated with other benign tumors or tumor-like diseases Loss exists and can even coexist with malignant tumors.

Aneurysmal bone cysts can also be transformed from non-ossifying fibroids, chondroblastoma, osteoblastoma, simple bone cysts, chondroma fibroma, and fibrous dysplasia. Aneurysmal bone cysts and the above lesions The connection is quite close, so the histology report must include the results of multiple lesions to exclude possible primary disease, the most common pre-primary disease: giant cell tumor (19-39%), followed by osteoblasts Tumor, hemangioma, chondroblastoma, chondromyxoid fibroma, simple bone cyst, fibroblastic cell tumor, eosinophilic granuloma and osteosarcoma.

Most of the aneurysmal bone cysts are filled with blood-like cysts of different sizes, dark red or brown, separated by fibrous tissue, and the wall tissue is divided into two types:

1 granuloma type, the thickness of the wall is different, mainly composed of abundant multinucleated giant cells and interstitial cells.

2 fiber type, mainly mature fibrous tissue, can also see unequal fiber ossification, vascular changes in the wall of the capsule see the small and medium veins obviously dilated and hyperemia, the blood vessel wall is thickened to varying degrees, due to aneurysmal bone cyst The pathological changes are mainly blood cysts of different sizes. The wall of the capsule is not a normal blood vessel wall, but consists of reactive interstitial cells and multinucleated giant cells. Under the fibrous tissue layer, there is reactive bone in the disease. The physical examination often has the histological features of the accompanying lesions, so it is necessary to carefully observe the characteristics of pathological changes.

Aneurysmal bone cyst prevention

Precautionary measures: The cortical bone of the cyst is relatively thin, prone to pathological fractures. Once the treatment causes certain troubles, it is necessary to pay attention to avoid stress on the affected area. Many people have formed a qualitative thinking. If there is a problem with bones, it is very unreasonable. The calcium required by human blood is limited. Blind supplementation will only reduce bone density and bone hyperplasia. The deviation of the diet always feels that the body is a disease that is lacking due to certain elements, and then eating a specific one or several kinds of foods can lead to serious malnutrition, and even worse, the disease will get better. Therefore, the meal should be arranged reasonably at this time. Because many doctors have publicized the disease, it is considered to be an incurable disease, causing extremely pessimistic feelings in patients. "The disease is not inherent to the human body. It can be removed, and it can not be ruled. It has not been done." Our ancestors said this for thousands of years, so that the disease must be kept happy. Mood.

Aneurysmal bone cyst complications Complications spinal cord compression

The disease may have different complications depending on the location of the lesion:

1. The lesion is located in the spine, which invades the spinal cord or compresses the nerve root. It can cause back pain, lower limb atrophy, incontinence, and even paraplegia.

2, the lesion occurs in the long bone, local swelling, hard, inactive, tenderness is not obvious or only mild tenderness, a few due to pathological fractures were found, and some showed local persistent pain, high skin temperature, hair Bright, superficial vein engorgement, and even similar to tumors.

Symptoms of aneurysmal bone cyst common symptoms spinal cord compression bone cyst bone destruction paraplegia joint fluid exudation action wall

Aneurysmal bone cyst can occur in any bone, but the most common site is 50% of long tubular bone, 20% to 30% of lesions occur in the spine. The common sites are as follows: long bones of the lower extremities, spine, upper limbs Tubular bone, clavicle, short tubular bones of the hands and feet, talus and facial bones, if aneurysmal bone cysts in the pelvis are often large.

The incidence of the spine involves both the posterior accessory and the vertebral body. The lesion grows and the adjacent vertebral body can be invaded. In the long tubular bone, the lesion is mostly located at the metaphysis and is on one side. About 1/4 of the lesion is located in the center. Aneurysmal bone cysts occurring in the middle of the backbone are not common. Aneurysmal bone cysts never occur in the epiphysis. Aneurysmal bone cysts generally do not grow beyond the cartilage, but after the bones mature, the lesions can develop to the bone ends. Regardless of where the aneurysmal bone cyst occurs, it appears to originate from the bone surface, subperiosteal, aneurysmal bone cyst from this position, up to the periosteum, invading the cortical bone.

The main clinical features of aneurysmal bone cysts are progressive local pain and swelling. Most patients often begin to find a deep mass on the limb, accompanied by mild pain. The development can be rapid or slow, about 1/3. Symptoms of patients are related to trauma. Pathological fractures are rare. If pathological fractures occur, obvious pain occurs, local skin temperature is often increased, there is obvious tenderness, occasional pulsation, and pathological fractures of aneurysmal bone cysts will not occur. There is a unique deciduous sign of benign bone cysts. The nearby joints may be swollen and the pain is limited. If the expansive lesions involve the articular cartilage, the joint activity is limited and the joint cavity is effusion.

When the lesion occurs in the spine, the pain symptoms are obvious, the vertebral body and the attachment are destroyed, and the spinal deformity occurs after compression. The spinal cord compression symptoms may occur, and the compression symptoms may gradually worsen or even paraplegic, and the compression symptoms may occur in the case of vertebral pathological compression fracture or acute bleeding of the lesion. Will suddenly appear.

The clinical symptoms and signs of aneurysmal bone cysts and changes in the course of the disease may vary depending on the speed of development, the location of the lesion and the degree of bone destruction. Those who develop rapidly show severe clinical signs and symptoms within a few months, and the swelling lesions grow. It can be very large, giving the impression of malignant tumors. The symptoms of slow development are also obvious in one or two years, and there are still no changes in the state of stagnation for a few years. The vast majority of patients usually do not exceed 6 months from the onset of symptoms to the time of treatment. In the case, without any treatment, the aneurysmal bone cyst can stop growing and ossify itself, and it can heal itself in 2 to 3 years.

According to different clinical manifestations, aneurysmal bone cyst can be divided into three phases:

1. Osteolysis period: There is simple bone destruction at the edge of the bone, there is slight swelling, and the interatrial septum is not obvious.

2, cystic lesions are obviously eccentric swelling, the interatrial septum can be seen in the lesion area, the lesion protrudes into the soft tissue, forming a thin shell.

3, calcification or ossification, scattered spots in the lesion area, small plaque or ossification, aneurysmal bone cysts often occur in 11-30 years old, more men than women, long bones of the limbs, the spine is good The site, especially the upper end of the femur, is more common, the clinical manifestations are local discomfort, mild pain and swelling, which vary according to the location of the site. When the lesion is located in the metaphysis or backbone of the long bone, the local inflated air-like translucent zone, There are trabecular bone or epiphyseal septa, lesions of the spine and flat bone, also appear as expansive light transmissive areas.

The disease is more common in adolescents with long bones and vertebrae of the extremities. There are no obvious symptoms, local puncture, and a hard shell feeling. It is easy to extract non-coagulated blood, which is characterized by polycystic bone destruction on the X-ray, or telecentricity. Balloon-like bulging should take into account the possibility of this disease.

Aneurysmal bone cyst examination

1. Aneurysmal bone cysts have typical X-ray findings. The long bones of the extremities are characterized by lesions at the diaphysis and metaphysis, but do not invade the epiphysis. The eccentricity protrudes out of the bone like a "balloon". The surface of the cyst is a thin layer of bone shell, the lesion is a localized translucent area, the boundary is clear, and the edge has a narrow hardening zone, which is divided by thick or thin irregular small sputum, which is honeycombed, located at the center of the bone, and expands to the periphery. Swelling, oval, consistent with the longitudinal axis of the bone, lesions in the spine mostly in the spinous processes, lamina, transverse processes, also bulging out of the bone, lesions can also involve the vertebral body, can lead to pathological fractures, a few Case lesions can invade adjacent vertebral bodies. The lesions of the tibia also show swelling changes. There are translucent areas. Tumors can occur in vertebral bodies or attachments. They are all bony inflated cystic translucent shadows. The larger ones can reach a diameter of about 10 cm. Light and thick trabecular bone can be seen inside, and if the vertebral body collapses, the typical X-ray features will be lost. At this time, attention should be paid to the expansion of the attachment, which can be used as a basis for diagnosis.

2, CT scan is helpful for determining the lesion, sometimes showing the liquid plane in the lesion, MRI can sometimes show the sponge-like appearance of the aneurysmal bone cyst, and can provide further information on the liquid, which can reflect Its vascular-rich characteristics show the lesions more clearly. CT scan has a high clinical value for pelvic and spinal lesions. CT scan can show the multi-focal liquid level in the cavity, so the differential bone cyst is identified. Great meaning.

3, MRI examination: MRI examination can also show multifocal liquid level, and can determine whether the intracavitary fluid is bloody, aneurysmal bone cyst MRI T1, T2 phase performance are low signal edge wrapped cystic defect, if suspect Care must be taken to observe the characteristics of the pre-primary disease species that may exist. Some aneurysmal bone cysts may have flocculated cartilage matrix components, which can be used to determine the source of histopathology.

4, gross anatomical examination: anatomical examination can be found that aneurysmal bone cyst is like a blood-rich sponge block, wrapped by periosteum, fibrous membrane divided into multiple intervals, with bloody fluid, microscopic view, arteries Tumor-like bone cysts are blood-rich interstitial spaces, composed of fibrous or immature woven trabecular frameworks, scattered with type I macrophages containing hemosiderin, fibroblasts, capillaries, and giant cells.

Diagnosis and diagnosis of aneurysmal bone cyst

diagnosis

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

Differential diagnosis

1. Isolated bone cyst: more common in the long bones of the extremities, often central type, with symmetry and mildly dilated bone necrosis, surrounded by dense hardening zone, the outer edge of the capsule wall is smooth and tidy, the inner edge is not smooth, and the bone growth gradually Moving to the backbone, often found due to pathological fractures.

2, giant cell tumor: the age of onset is large, the lesion is mostly located under the joint of the long bone end, the joint surface is often the outline of the tumor. Because the tumor is longitudinal, the growth of the transverse line is almost the same, so the tumor is mostly spherical, and there is a soap bubble in the tumor. Ossification and reactive osteosclerosis are rare, and the incidence of aneurysmal bone cyst is mild. The lesions are mostly located at the metaphysis, rarely invading the epiphysis, and often have different degrees of osteosclerosis.

3, non-ossifying fibroids: often invade the cortical bone, spread along the backbone, lobulated, hardened at the edges, sometimes incomplete edges, and even bone cortical fracture.

4, cartilage mucin-like fibroids: more common in adolescents, eccentric growth, lobulated, and divided into a room-like, when there is no encapsulation into the soft tissue, there are spotted and patchy calcification in the destruction zone.

Occasionally, because of the severe pain, and when the part of the bone shell is destroyed and disappeared on the X-ray, the bone cortex should not be mistaken for malignant bone tumor. The diagnosis of aneurysmal bone cyst is sometimes difficult. Many cases cannot be diagnosed before operation. .

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