Giant cell tumor of bone

Introduction to giant cell tumor of bone Giant cell tumor of bone (GCTB) is often called benign giant cell tumor or osteoclast. It is one of the more common primary bone tumors. Bone giant cell tumor is a benign lesion of bone, usually single and locally invasive. It is also believed that giant cell tumor of bone is a potentially malignant tumor. This tumor is neither completely benign nor completely malignant, but it is between these two extremes, and its degree of invasion is different. Some giant cell tumors can obtain long-term control after relatively simple surgery, and some Giant cell tumors can appear to spread and metastasize. In the surgical staging system of the bone tumor proposed by the American Society of Skeletal Muscle Oncology in 1980, giant cell tumor of the bone was officially classified as a low-grade malignant mass. basic knowledge The proportion of illness: 0.001%-0.008% Susceptible people: no specific population Mode of infection: non-infectious Complications: fractures paraplegia

Cause of giant cell tumor of bone

Cause (80%)

The cause is not clear. Tumor tissue is rich in circulation, soft and brittle, like granulation tissue, easy to hemorrhage, fibrous mechanized area and hemorrhage area, divided into three degrees according to benign and malignant degree: once: about half of giant cell tumors belong to this category. For obvious benign, there are many giant cells, and there are few cell divisions. It is necessary to treat all tumors once to be judged as a tumor. Second degree: malignant or benign is not easy to distinguish, there are more interstitial cells, and giant cells are less than once. Third degree: obvious malignancy, less occurrence, more interstitial cells, large nuclei, morphology such as sarcoma, more cell division, less and smaller giant cells, and fewer nuclear numbers, one or two degrees can be converted to three degrees.

Pathogenesis (10%)

The pathogenesis of giant cell tumor of bone is still unclear. Compared with other solid tumors, the tumor tissue of giant cell tumor is very soft and fragile, the blood supply is rich, the tumor tissue is reddish brown, and the yellow hemosiderin substance is visible to the naked eye. Deposition, cystic changes are more common, and the near-edge part can sometimes scrape out the hard and tough tissue. Because of the more reactive fibrous tissue components, the pathological examination should be taken from the typical tumor tissue at the central part, otherwise it will make a wrong judgment. Microscopic features of giant cell tumor: multinucleated giant cells are evenly distributed in a large number of round, elliptical or fat short-stem-shaped mononuclear interstitial cells, and their nuclei are very similar in volume, shape and staining. Tumors are rich in blood vessels, often accompanied by hemorrhage. Hemosiderin particles are sometimes seen in the interstitial cells in the hemorrhagic area. Multinucleated giant cells have no phagocytosis. The number of nuclear multinucleated cells varies from several to several hundred. The occurrence of pyknosis and deep staining shows the phenomenon of aging and degeneration; the core of most multinucleated giant cells shows normal structure, which is a young giant cell, indicating that multinucleated giant cells have aging process in the body, and the nuclei of multinucleated giant cells are rarely present. Mitosis, as the aging process progresses, the phenomenon of nucleus accumulating in the center of giant cells becomes more apparent. Only mononuclear interstitial cells have the ability to divide, and multinucleated giant cells have no dividing potential.

Giant cell tumor prevention

First, to maintain mental optimism, a large number of studies have fully confirmed that any bad mood can weaken immune function, is a strong "cancer promoting agent", and mental optimism can improve the body's immune function, is the best "antibody" Therefore, it is necessary to cultivate a cheerful and optimistic personality, learn to self-regulate emotions, be generous and generous, smile and open, and ensure mental health.

Second, pay attention to cleanliness, modern research found that 80% to 90% of cancers are indexed by carcinogenic factors in the living environment, so it should be developed into good hygiene habits, such as brushing teeth, mouthwash is a good way to prevent oral cancer; Diligent clothes, often take a bath, keep the lower body clean, can prevent penile cancer, uterine cancer, etc.; avoid and minimize the absorption of oil and other abnormal gases, can reduce the incidence of lung cancer; not excessive sun exposure, can prevent skin cancer.

Third, actively participate in sports, exercise can improve the body's immune function, make the blood flow smooth, push out new, some cancer patients after physical exercise, cancer cells can self-resolved, so adhere to exercise, persevere, will enhance physical fitness, prevent disease disease.

Fourth, seriously put a good diet, not partial eclipse, do not eat the same food repeatedly, diet is not excessive, full, at the same time do not eat mold, burnt, too hot, hard and spicy food, usually eat more anti-cancer food Fresh vegetables and fruits rich in carotene and vitamin A, garlic, mushrooms, kelp, tomatoes, spinach, cucumber, eggplant and milk, soy products, tea, royal jelly, etc., all have a certain anti-cancer effect.

5. Smoking cessation and less alcohol, smoking has a hundred harms and no benefit. Tobacco contains more than 30 kinds of toxic substances such as nicotine. The incidence of lung cancer is high, and the incidence of esophageal cancer, oral cancer, stomach cancer, nasopharyngeal cancer, etc. It is also significantly higher than the average person. In order to be healthy, smoking should be stopped. Drinking should also be scientific. After drinking a small amount of wine, beer and other low-alcohol wines, it can help the blood and help digestion, but drinking a lot of hard alcohol can damage the digestive tract and cause the original. Sexual liver cancer and other cancers of the digestive tract, so alcohol should not be drunk, especially on an empty stomach.

Giant cell tumor complications Complications

About 1-6% of patients with giant cell tumor of the bone have lung metastasis, and the prognosis is relatively good. In some cases, the metastases can be cured by surgical resection, and the metastases remain unchanged or self-resolved for many years. However, about 20% In the case of lung metastasis, the disease can develop rapidly, leading to death, extrapulmonary metastasis is rare, and the giant cell tumor of the bone can undergo malignant transformation and become a giant cell sarcoma of the bone. The degree of malignancy is greatly improved, and the mechanism of malignant transformation is still unclear. A large number of cases have confirmed that giant cell tumor of the bone can be secondary to sarcoma after radiotherapy, suggesting that radiotherapy can accelerate the malignant progression of giant cell tumor of bone.

Giant cell tumor of bone can be complicated by pathological fracture. In patients with spinal lesions, the tumor can compress the nerve root or spinal cord, causing root pain or paraplegia.

Giant cell tumor symptoms common symptoms joint swelling joint pain shoulder joint activity limitation tibia pain tibia pain

The predilection sites of giant cell tumor of bone have been described in pathology. Most of the patients are young adults aged 20 to 40, accounting for more than 80% of the total. The male and female morbidity are equal, and more than 50% of the cases have a history of injury before the onset. Tumor growth is active, the average disease period is about 10 months, the earliest complaint is pain, followed by swelling, pain is not severe, and does not interfere with sleep, about 16% of cases are due to pathological fractures before going to the hospital for treatment.

The clinical manifestations of giant cell tumor of bone are not specific. When the lesion destroys the cortical bone and stimulates the periosteum or when the strength of the bone decreases, pathological fractures will occur. Clinical symptoms can be produced. Like most bone tumors, it is often caused by local swelling and Found in pain.

Symptom

The degree of clinical symptoms varies, and it is generally independent of the size of the tumor at the time of the visit. Some patients are treated for pathological fractures and have extensive bone destruction at the time of presentation.

(1) Pain: more common in the early stage, generally not intense, the cause is due to tumor growth, increased intramedullary pressure, occurs in the spine, the tumor can compress the nerve or spinal cord, resulting in corresponding neuroradial pain or paraplegia, a few The patient may seek medical attention for a pathological fracture.

(2) local swelling, lumps: appearing later than pain symptoms, swelling is generally light, due to changes in bone shell expansion and reactive edema, such as lesions penetrate the cortical bone, forming a soft tissue mass, swelling is obvious, swelling Gradually increase slowly, sometimes rapidly, mostly due to intratumoral bleeding.

(3) joint dysfunction: local infiltration of long bone bone tumor can cause joint dysfunction, tumor rarely wears articular cartilage, but can cause joint surface collapse or weakness, sometimes the tumor volume is larger, the range exceeds the joint, but X-ray films show that the articular cartilage surface is still intact, which is one of the characteristics of this tumor.

2. Signs

(1) Local skin temperature rise, vein exposure: indicates local hyperemia and reaction area of the lesion, especially the destruction of cortical bone. When the mass of soft tissue is formed, the skin temperature is increased obviously, which is also related to the blood richness of the tumor.

(2) When the bone shell is intact and thick, it touches the hard and tough mass. The thin bone shell can be elastic. If the bone shell is destroyed or there is no bone shell, it is a cystic mass. Sometimes the tumor appears pulsating, indicating that the tumor is congested obviously. .

(3) Giant cell tumor of the bone that occurs in the spine, which can cause vertebral compression fracture, spinal cord injury and paraplegia. It can cause pain in the temporal region of the humerus, numbness and urinary dysfunction in the saddle area, and the anus can be diagnosed before and after the sputum. Mass.

On the x-ray photograph, the typical giant cell tumor of the bone is a soapy foam-like cyst-like shadow. It is located on the side of the long bone end and gradually expands toward the center. Finally, the entire bone end and part of the metaphyseal end are destroyed and expand to the periphery. However, the tumor rarely penetrates the articular cartilage surface, and the bone wall around the tumor is clear and tidy. There may be a small amount of bone dense at the junction with the diaphysis. In the cystic transparent shadow, there is no calcification or new bone, and occasionally self-healing or The semi-self-healing phenomenon is mostly caused by pathological fractures and massive hemorrhage inside the tumor. In clinical practice, the typical x-ray signs of soap foam are rare. In most cases, the surrounding bone wall is dilated, and the boundary is clear, but there is no cyst-like cyst. Signs, the development of osteolytic changes after pathological fractures is particularly significant, and must be differentiated from central osteofibrosarcoma.

In most cases, diagnosis can be made based on medical records, clinical and x-ray signs, but tissue biopsy is very important in the diagnosis of giant cell tumor of bone. It plays a guiding role in the determination of treatment and prognosis. Therefore, pathology The examination should be as thorough, extensive, and careful as possible. The results of a small piece of tissue examination can be used to infer the nature of the entire tumor. It is difficult to achieve correct classification. Surgery can be based on frozen sections or biopsy, combined with clinical and x-ray signs. Performing, postoperative resection or scraping of the specimen should be more comprehensive examination, and certainly better observation or further treatment after classification.

The lesion is around the knee joint, swelling, pain, and the X-ray shows a uniform and osteolytic destruction of the bone end. It is soapy foam, and the stromal cells and multinucleated giant cells are under the microscope.

Examination of giant cell tumor of bone

The pathology is as follows:

1. Seen by the naked eye: During surgery, the lesions are concealed under the normal cortical bone or reactive bone. The soft tissue is easily peeled off. After opening the window, the blood tissue is rich and brittle, almost sponge-like. It is easy to use a scalpel or a spatula to remove the diseased tissue into a soft reddish-brown tissue with golden tissue interspersed.

2. Microscopic findings: The main microscopic features of giant cell tumors are: monomorphic stromal cells, small, uniform multinucleated giant cells, abundant blood vessels and obvious necrosis. The stromal cells contain large vacuolar-like nuclei with obvious nuclear membranes. They contain one or two nucleoli. The giant cells are fused by stromal cells, which are small and uniform. The characteristics of the nucleus are the same as those of stromal cells. The somatic or giant cell network makes it difficult to distinguish between stromal cells and giant cells. Together with the blood vessels, these cells constitute a viable tumor tissue with a soft, brittle texture and a reddish-brown color. In the other parts of the lesion, completely different images can be seen. These areas are composed of hard yellow tissue, which is characterized by large areas of necrosis, residual images of multinucleated giant cells, mature fibrous tissue, and iron-containing blood. The flavin particles are occasionally visible in small, bulky, fat-filled tissue cells.

Tumor cell plugs can also be seen in the capillaries and venules of the diseased tissue. At the site where the tumor invades the articular cartilage, the tumor cells appear to directly destroy the articular cartilage.

3. Pathological features: The tumor tissue is light red fragile granulation tissue, which can be dark red due to hemorrhage. It is often mixed with necrotic tissue. The tumor has different sizes of cysts, containing a small amount of bloody or brownish yellow liquid. The cavity is covered with a smooth membrane, and the vascular network is abundant under the microscope. It is filled with a short-shaped, uniform shape, round or oval interstitial cells and scattered multinucleated giant cells, similar to giant cell nuclei, according to interstitial cells. The degree and degree of differentiation, as well as the number of giant cell nuclei can be divided into different grades, grade I is benign, interstitial cells are less, giant cells are large, nuclear is numerous, and occasional lung metastasis; grade II is between good and malignant, There are many interstitial cells, the nucleus has mild heteromorphism, there are mitotic figures, fewer giant cells, less nuclei; grade III is malignant, interstitial cells are densely populated, nucleus has different degrees of heteromorphism, and there are many mitotic figures. Giant cells are small, with few nuclei and irregularities.

1. X-ray examination is located at the end of the long bone (osteophyte), showing central or eccentric osteolytic destruction, and invading the metaphysis, extending to the joint can completely destroy the subchondral bone. In general, the lesion The boundary is clearer and expansively changed. There is a reactive thin layer of bone shell around the lesion. The inner wall of the bone shell may have osteophytes protruding in the lesion, forming a so-called "lobular" or "soap-like" change under the X-ray. In some cases, there may be no swelling changes. The tumor may destroy or break through the cortical bone and enter the surrounding soft tissue to form a soft tissue mass. The periosteal reaction is generally absent. When there is a pathological fracture, it may be accompanied by bone. Osteoporosis, giant cell tumor of bone has no calcified tumor matrix, often accompanied by pathological fractures. Giant cell tumor of the humerus, the lesion is often eccentric, and often involves one side of the ankle, and the chordoma is often located in the tibia. Central, the giant cell tumor of the bone located in the spine is easy to involve the vertebral body and pedicle, and the kyphosis is secondary to the collapse of the vertebral body. The anterior structure of the spine is characteristic of giant cell tumor of the bone. Aneurysmal bone cyst, osteoblastoma often destroys the posterior structure of the spine. In some patients whose tarsal plate is not closed, osteolytic destruction occurs at the metaphyseal end, and then passes through the tarsal plate and the X-ray film can show its General characteristics, but still not enough to confirm the diagnosis. Occasionally occurs in the bone protrusions, such as large and small, flat bones such as pelvis and scapula are rare, it is also reported that giant cell tumors occur in the hands and feet, and the spine (except the humerus) is also rare.

Giant cell tumors of the bone are characterized by osteolytic destruction and a wide transition zone. The cortical bone of the lesion is often dilated and thinned. The residual osteophytes in the lesion appear as a separation on the X-ray, and the tumor can also invade the surrounding area. Soft organization. The X-ray findings of some invasive osteolytic lesions are similar to giant cell tumors of the bone, such as aneurysmal bone cysts and brown tumors in hyperthyroidism.

2. CT examination: CT examination is more than X-ray film and tomography in determining the tumor boundary. The tumor is physically changed. The CT value is similar to that of the muscle. Sometimes the tumor contains cystic cavity, but it is rarely like an aneurysmal bone cyst. Seeing the liquid plane, the reactive bone shell is different from the normal cortical bone and less calcified. The CT examination is helpful for the relationship between the articular cartilage and the joint cavity and the degree of tumor invasion of the surrounding soft tissue. The new double-slice CT is injected intravenously. After the contrast agent, reconstruction of each level can be performed to show the blood vessels in the tumor, and the angiography can be performed.

3. Magnetic Resonance Imaging (MRI): Magnetic resonance imaging is the best imaging method for giant cell tumor of bone. It has high-quality contrast and resolution. The tumor exhibits low-intensity signal in longitudinal relaxation time (T1-weighted image). The transverse relaxation time (T2-weighted image) is expressed as a high-intensity signal, so it is best to use T1-weighted images when looking at intramedullary lesions. T2-weighted images are best used when observing extracortical lesions. MRI shows any extra-osseous invasion and joints. There is an advantage in the degree of involvement, and CT is characteristic of observing cortical bone destruction and reactive bone shell. MRI and CT are very useful for early detection of tumor recurrence. Most lesions are composed of a mixture of living tissue and necrotic tissue. The lesion has an uneven MRI signal, and the high signal and low signal regions exist in phase.

The spread of subchondral lesions to adjacent joints usually occurs at the starting and ending points of the intra-articular ligaments. The more common is the cruciate ligament of the knee joint. It is relatively rare to spread directly through the articular cartilage into the joint, but it can happen. Giant cell tumor The tendency to directly invade and destroy articular cartilage, although not unique to it, is more common than any other tumor (including malignant tumors). Spreading through the pathological fracture into the joint is not common, but it can occur, so when there is a pathological fracture When it occurs, it is necessary to check the presence or absence of intra-articular spread, and observe the whole lesion specimen. The appearance is very diverse, and some lesions are completely composed of soft, blood-rich and reddish-brown fragile tissue. The water content is high, so it shows a high signal with uniform texture on MRI.

Other lesions consist mainly of hard yellow cheese-like tissue or sponge-like necrotic tissue, which contains almost no vascular tissue. These areas are composed of necrotic tumor tissue and large, fat-filled tissue cells.

Diagnosis and diagnosis of giant cell tumor of bone

Differential diagnosis

Giant cell repair granuloma is common in adolescents between the ages of 10 and 20, and it is easy to develop the mandible. It is now believed that the mandible is usually not a true GCT but a giant cell repair granuloma. The micronucleated giant cells are small and medium in size. Uneven distribution, often gathered in the site of hemorrhage, necrosis and hemosiderin deposition, and the formation of bone and bone tissue, the lesion has a good prognosis after simple curettage.

Aneurysmal bone cysts: occur in adolescents under the age of 20, with good vertebrae and flat bones, but can also occur in long bones, X-ray similar to GCT, eccentric swelling of the bone, osteocortical ablation, and GCT mirror The difference is that the multinucleated giant cells are unevenly distributed and are located near the vascular cysts and hemorrhagic foci. The cell bodies are small, and the interstitial is mature fibrous tissue. A single lesion scraping a quarter will recur, and a large mass is removed or scraped. Combined with bone grafting, the multi-nuclear giant cell bone lesion is very complicated. It is easy to cause misdiagnosis when it is not alert. For the patient is a child, the vertebrae, the jaw bone and the hand and foot bone except the humerus, the lesions are often multiple, usually not GCT. It is particularly worth mentioning that GCT can be misdiagnosed as a GCT with pathological fracture due to necrosis, hemorrhage and multinucleated giant cell response, and should be identified.

Isolated bone cyst: occurs frequently in the metaphysis of the adolescent osteophytes before they heal, showing a symmetric expansion and less separation.

Chondrogenic neoplasms: occur in the long bones of the 20-year-old orbit, often have calcifications in the tumor, less space, and clear edges.

Non-ossifying fibroma: more common in adolescents, occurs in the long tubular bone backbone, eccentric growth, mostly along the long axis, clear edges, hardened edges.

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