What are the diagnostic indicators for osteosarcoma

When people suspect that they have osteosarcoma, they often go to the hospital for a series of tests to get a final diagnosis. According to a survey, about 20% of osteosarcoma cases have already metastasized to the lungs when diagnosed. Therefore, early diagnosis is very important for the treatment and prognosis of osteosarcoma. Osteosarcoma is a disease with relatively uncommon symptoms after onset. So what are the diagnostic indicators of osteosarcoma? Let's learn about it together.

1. Laboratory examination of osteosarcoma Laboratory examination Anemia, elevated or normal white blood cell count, increased erythrocyte sedimentation rate, and increased serum alkaline phosphatase

2. X-ray examination of osteosarcoma

1. Changes in cancellous bone and medullary cavity The most characteristic change of osteosarcoma is bone hyperplasia, among which tumor new bone formation is an important feature, mixed with reactive bone hyperplasia. X-ray shows bone sclerosis and whitening. There are several types of changes in the cancellous bone and medullary cavity of the metaphysis: ① uniform ground-glass density increase; ② foggy, patchy or mass-like tumor new bone formation; ③ reactive bone sclerosis; ④ bone destruction

2. Changes in the bone cortex In the early stage, the bone undergoes osteolytic destruction, and the bone density decreases, which is manifested as sieve-like thin translucent lines. Later, the cortical surface becomes uneven, and the bone density increases after the formation of tumor bone in the osteolytic area.

3. Periosteal reaction

① Linear or onion-skin-like periosteal reaction: The linear one is a very thin layer of periosteal new bone parallel to the bone shaft, while the onion-skin-like one is many layers.

②Vertical periosteal reaction: The new bone of the periosteal bone is oblique or perpendicular to the cortical bone, with a higher density on the outer edge, smooth and neat, and clear edges.

③Codman triangle (cuff syndrome) and solar radiation phenomenon.

3. CT examination of osteosarcoma can accurately show the tumor. Plain scans show different degrees of bone destruction, irregular cortical thickening and bone sclerosis. Periosteum hyperplasia shows high density. Tumors invade the medullary cavity, increasing the density of low-density intramedullary tissue and spreading. If skip metastasis is formed, the bone cortex will be interrupted. CT enhanced scans can clearly show the edge of soft tissue and help show the relationship between the tumor and nearby large blood vessels.

4. The imaging characteristics of osteosarcoma by MRI examination depend on the main cell type in the tumor tissue and the presence or absence of hemorrhage and necrosis.