Ewing sarcoma

Introduction to Ewing's sarcoma The traditional concept of Ewing'ssarcoma is believed to be the primary malignant bone tumor with mesenchymal connective tissue originating from the bone marrow and small round cells as the main structure. The new modern concept is: small round cell tumors of bone or soft tissue of the origin of the neuroectoderm. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: paraplegia fracture

Ewing sarcoma etiology

(1) Causes of the disease

The cause is unknown.

(two) pathogenesis

In the early stage, when the tumor is still confined to the bone, the texture is firmer. Once the cortical bone is destroyed and the tumor invades the soft tissue, the texture becomes soft and fragile. The appearance of the tumor is a glossy fusion round nodule, which is grayish white. After secondary changes, it may be purple-red or yellow due to necrosis. When severely degenerated, it can form a cystic cavity containing liquefied necrotic tissue. It can be seen under the microscope: typical tumor cells are relatively uniform in size, small and round, no Clear cytoplasmic boundaries, typical or atypical mitotic figures are sometimes seen in tumor cells that are closely clustered together. Silver staining shows that reticular fibers often surround large tumor cells, forming lobulated septa, rarely interspersed with tumors. Between cells, this is one of the important identification points of primary reticulocyte sarcoma (non-Hodgkin's lymphoma) with bone, which can be expressed by histochemical methods such as periodic acid Schiff (PAS). There is a large amount of glycogen in the cytoplasm (also confirmed under electron microscopy), which can be distinguished from reticulocyte sarcoma and neuroblastoma.

Ewing sarcoma prevention

Diet is a big problem, pay attention to diet, eat light food, and supplement certain nutrients.

Ewing sarcoma complications Complications

Occurred in the spine often complicated by paraplegia and incontinence, combined with pathological fractures are rare.

Ewing sarcoma symptoms Common symptoms Persistent pain Soft tissue swelling ESR increased urinary incontinence Paraplegia

Generally speaking, any bone can be affected, and the long bone is more than the flat bone. It is also reported that the two are basically equal. Among them, the long bone occurs in the femur, the tibia, the tibia, the tibia, and can invade the metaphysis and the trunk; the flat bone occurs in the tibia. , scapula, ribs, jaw, humerus.

The main symptoms are local pain, swelling, and the pain is often not severe at the beginning. It is intermittent, exacerbated during activity, and gradually increases, becoming persistent pain. If the position is superficial, the mass can be found early, there is tenderness, skin temperature High, red, poor general condition, often accompanied by fever, anemia, increased white blood cell count, increased erythrocyte sedimentation rate, sometimes very similar to acute blood-borne osteomyelitis, more special cases of anti-inflammatory pain after the application of antibiotics, body temperature can be reduced Normal, followed by repeated symptoms, occur in the spine often accompanied by severe root pain, paraplegia and incontinence, Ewing sarcoma develops very fast, early can occur extensive metastasis, involving the body skeleton, visceral and lymph, but pathological Fractures are rare.

1. X-ray diagnosis: Ewing sarcoma is difficult in the early stage of clinical diagnosis and X-ray film diagnosis. Sometimes even biopsy is difficult to diagnose because it does not include tumor cell nest. Electron microscopy and immune tissue are needed. Chemical and molecular methods can be diagnosed. Therefore, it is necessary to combine clinical, imaging, and pathological analysis. The local pain is severe, the swelling develops rapidly, the systemic condition deteriorates rapidly, and the anti-infective treatment is ineffective, or effective at the beginning, and soon When it becomes ineffective, it should be considered to diagnose the disease. On the X-ray film: the metaphysis of the long bone is involved, its position is closer to the backbone than the osteosarcoma, and there is a reactive new bone in the tumor area. The typical "onion skin-like" periosteal hyperplasia The diagnosis is easier, but most cases are not typical, but mainly manifested as bone destruction, flat bone has osteolytic, hardening or mixed destruction, no obvious special performance, but other malignant tumors often have their own special signs, short-term Repeated radiography is helpful for diagnosis. CT and MRI are superior to X-rays in soft tissue swelling and mass boundaries around the diseased bone, and MRI is more sensitive than CT. And can show the bone marrow status, in histology, the material should be sufficient, should include soft tissue, periosteum, bone and tumor bone, microscopically uniform small tumor cells can be seen under the microscope, histochemical examination of most tumor cells containing glycogen ( More than 90).

2. Genetic diagnosis: Cytogenetic studies have found that Ewing's sarcoma has a translocation of chromosomes 11 and 22 (11, 22) or a translocation of chromosomes 21 and 22 (21, 22) resulting in the EWS gene. With FLII gene or ERG gene rearrangement, about 86% of Ewing's sarcoma can detect ectopic chromosomes 11 and 22; reverse transcription PCR (RT-PCR), chromosome in situ hybridization (FISH) Hybridization with DNA molecules can detect transcription of approximately 90% of Ewing's sarcoma with EWS/FLII fusion gene and 5% to 10% of EWS/ERG fusion gene, which is important for the diagnosis of Ewing's sarcoma.

Ewing sarcoma examination

White blood cells often increase up to (10.0 ~ 30.0) × 109 / L, blood cell sedimentation rate is accelerated, due to a large number of new bone formation of periosteum, serum alkaline phosphatase can be slightly increased, which is of great significance for adult diagnosis, tumor cell glycogen staining Positive; there are also reports in the literature that the positive Bence-Jones test has a certain diagnostic value for this disease.

1. X-ray performance: Ewing sarcoma has a great difference in X-ray film, and its basic X-ray manifestation is a wide range of osteolytic invasive bone destruction and bone hyperplasia, which can occur in the backbone or in the trunk. The sacral or diaphysis and metaphysis are involved at the same time. The early metastasis of the metaphysis in the long bones has a small spot-like density reduction zone, the trabecular bone is not clear, and the inner surface of the cortical bone is blurred. The worm-like or rat bite, followed by the same change in the cortical bone, the edge is blurred, the cortical bone is thinned to varying degrees, the periosteum is swollen, and the periosteal hyperplasia is changed by onion-like changes, about half of which is visible, sometimes Codman is visible. Triangular, and there may be symmetrical fusiform soft tissue swelling or soft tissue mass (Fig. 1). Some may also have radial or perpendicular to the cortical bone. The bone shape is consistent. When it occurs in the diaphysis, the early lesion is located in the medullary cavity. There may be a small amount of periosteal reaction, and the X-ray film is not observed by the former. As the disease progresses, the spotted osteolytic bone destruction, such as worm-like shape, is merged into patchy shape and spreads along the longitudinal axis of the backbone. There will be a lot of The onion-like periosteal reaction can be seen in the Codman triangle. Symmetrical ridge-shaped soft tissue swelling or soft tissue mass can be seen around the diseased bone. It can also appear as a bone needle that is radially arranged perpendicular to the backbone, with uniform density and uniform morphology.

The X-ray findings of Ewing's sarcoma, which occurs in the flat bone, can be characterized by osteolytic, sclerotic and mixed bone destruction, and some even have swelling changes (Fig. 2), and some can also have radial needle bone. According to the author (1986), needle-shaped new bone is a unique manifestation of Ewing's sarcoma, and the incidence rate is not low. The incidence of tumors in the pelvis is higher. The lesions in the vertebral body are characterized by vertebral bodies. Extensive bone destruction, adjacent vertebrae can be affected, more without periosteal reaction, visible soft tissue shadows around the paravertebral.

2. Features of CT examination: The classification of bone destruction is the same as X-ray, and it is also divided into three types. There is obvious large soft tissue mass in the diseased bone circumference. The internal texture is relatively uniform, the density is similar to the muscle, and the broken bone is occasionally seen in the tumor. And reactive osteogenesis, showing an increased density image.

3. Characteristics of MRI examination: Obvious large soft tissue mass can be seen in the periarticular bone, and the T1 weighted image shows the same or slightly higher signal as the muscle, and the T2 weighted image is a distinct high signal; the boundary of the lesion can be clearly defined. ; clear to the bone marrow.

4. Characteristics of bone scan: 99mTc bone scan showed that reactive osteogenesis and pathological fractures generally showed moderate intensity irregular concentration; soft tissue mass around the diseased bone often had no nuclides concentration; periosteal reaction area showed nuclides Concentration.

Diagnosis and diagnosis of Ewing sarcoma

Differential diagnosis

Mainly need to differentiate from acute suppurative osteomyelitis, primary reticulocyte sarcoma, neuroblastoma bone metastasis, and osteosarcoma.

1. Acute suppurative osteomyelitis: The disease is acute, and it is accompanied by high fever. The pain is more severe than that of sarcoma. The suppuration is often accompanied by jumping pain. The nighttime pain is not aggravated. Some cases are accompanied by chest or other parts of the infection. X-ray films on the affected bone changes are not obvious, and then spotted sparse destruction in the cancellous bone cancellous bone, bone hyperplasia occurs quickly at the same time as bone destruction, and more dead bones appear; puncture examination, in the early stage of osteomyelitis It can be aspirated by bloody liquid or purulent liquid, and the culture of bacteria is positive, but Ewing's sarcoma is not. The exfoliative cytology is helpful for diagnosis. The osteomyelitis has obvious effect on anti-inflammatory treatment. Ewing sarcoma is extremely sensitive to radiotherapy.

2. Primary reticulocyte sarcoma: Most occur in 30-40 years old, with a long course of disease, good general condition, no serious clinical symptoms, X-ray manifested as irregular osteolytic bone destruction, sometimes ice-like, There is no periosteal reaction, pathological examination, the nucleus is more irregular, pleomorphic, reticulated fiber is rich, surrounded by tumor cells, histochemical examination: no glucosamine in the cytoplasm.

3. Neuronal cell bone metastasis: more common in children under 5 years old, 60% from the retroperitoneum, 25% from the mediastinum, often no obvious symptoms of primary disease, metastatic pain, swelling, and more pathological fractures, Urine examination of catecholamines is elevated, often difficult to identify on X-ray films; pathologically neuroblastoma cells are pear-shaped, forming a true chrysanthemum-like; under the electron microscope, there are neuroendocrine granules in the tumor cells.

4. Osteosarcoma: The clinical manifestations of fever are mild, mainly pain, heavy at night, and the tumors that penetrate the cortical bone into the soft tissue are mostly on the side of the bone. There is ossification in the bone. The size and shape of the bone reaction are often inconsistent. The Codman triangle and the radial bone needle were changed, and the pathological tumor cells were not arranged in a pseudo chrysanthemum.

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