Expert explanation: Osteosarcoma diagnosis method

Osteosarcoma has a high degree of malignancy and is a common primary malignant tumor. According to surveys, about 20% of osteosarcoma cases have already metastasized to the lungs when diagnosed. Early diagnosis is very important for the treatment and prognosis of osteosarcoma. Imaging examination X-rays show bone hyperplasia, osteolytic destruction, periosteal reaction, and obvious new bone hyperplasia under the periosteum, showing a typical Codman triangle (cuff sign) and soft tissue mass.

Early detection of sarcoma requires clear examination and diagnosis methods for sarcoma cancer. So what are the diagnostic methods for sarcoma cancer?

1. It is common in adolescents aged 15 to 25 years old, and is more common in the distal end of the long bones of the limbs. It is most common above and below the knee joint.

2. The main symptom is local pain, which is intermittent dull pain at first and quickly turns into continuous severe pain, especially at night.

3. The local skin temperature is high, the veins are dilated, the mass grows rapidly, there is tenderness, tremors and vascular murmurs may occur, and there may be pathological fractures and joint dysfunction.

4. Systemic toxic reactions, loss of appetite, weight loss, and finally exhaustion and cachexia.

5. Anemia, increased white blood cell count, rapid erythrocyte sedimentation rate, and increased alkaline phosphatase.

Detailed examination and diagnosis methods of osteosarcoma

1. Microscopic examination: Bone tumors have little or no bone under the microscope, with occasional or scattered bone-like tissue, but a large number of tumor osteoblasts, primitive differentiation, uneven cytoplasm, unclear cell membrane, and large nucleus. Two relatively rare types of giant cells can also be found under the microscope, with as many as 3-10 nuclei, and the other is a foreign body giant cell, which is similar in morphology to the giant cells of giant cell tumor of bone.

2. Laboratory examination: When serum alkaline phosphatase is normal, it does not negate the diagnosis of osteosarcoma, but it plays a certain supporting role in the diagnosis of osteosarcoma.

What tests are commonly used to diagnose osteosarcoma?

1. Imaging examination X-ray shows bone hyperplasia, osteolytic destruction, periosteal reaction, obvious new bone hyperplasia under the periosteum, showing the typical Codman triangle (cuff sign) and soft tissue mass.

2. Pathological cytological examination: Incisional biopsy or percutaneous puncture biopsy can further clarify the diagnosis. It is generally divided into fibroblastic type, osteoblastic type, and vascular type.

Lung and local X-rays are important steps in diagnosing osteosarcoma and determining the prognosis of sarcoma. The following aspects describe the linear signs of osteosarcoma:

(I) Local soft tissue tumors: If the tumor occurs in the deep layer of the periosteum, or the tumor has broken through from the inside of the bone to the surrounding area, irregular patterns can be found in the soft tissue on the X-ray.

(II) Periosteal changes: Early periosteal changes are triangular periosteal new bone formation, followed by solar radiation-like periosteal reactions. In the late stage, as the tumor expands to the periphery, the triangular new bone also becomes defective and moves toward the middle of the bone shaft. The solar radiation-like new bone trabeculae, squeezed and destroyed by tumor cells, form a disordered state like fluffy hair. Finally, as the tumor continues to proliferate, the new bone may completely disappear, and the soft tissue may show irregular tumor shadows.

(III) Cortical bone changes: When osteosarcoma occurs in the periosteum or cortical bone itself, the earliest and most important change is mild destruction and loosening of the cortical bone on one side. If the tumor is sclerotic osteosarcoma, in addition to bone destruction and loosening, there are also irregular tumor bone hyperplasia shadows. Therefore, in the X-ray, it can be found that the organization is disordered, there is no texture, and the very dense tumor bone shadow overlaps the loose and damaged bone.

(IV) Changes in cancellous bone: Osteosarcoma that occurs in the medullary cavity is mostly osteolytic, with abundant blood supply and rapid growth. Bone destruction is from the inside out, rapid and extensive, and uniform around the periphery, so periosteal reactive new bone is not easy to form. X-ray signs may be cystic, so it is easy to cause pathological fractures.

(V) Changes in the lungs: Pulmonary metastases are generally found within 4-9 months of the appearance of the primary tumor. Pulmonary metastases are difficult to detect in the early stages, so if no metastases are found on lung X-rays, it does not mean that there are no metastases in the lungs. Generally, lung X-rays should be taken again every 2-3 months, and observation should be continued for 2-3 years. If no metastases are found in the lungs, the possibility of finding them will gradually decrease. Most metastases are distributed at the edges of the lung lobes, and occasionally they may occur near the hilum of the lungs, which should be distinguished from calcified lymph nodes. Metastases are cotton balls of varying sizes. Those that grow slowly produce more bone and have a higher density. Some metastases do not produce tumor bone at all, so their density is no different from metastases of other soft tissues.