Osteosarcoma is also called osteosarcoma.
Developed from mesenchymal cells, it is a primary bone malignant tumor. In primary bone tumors, the incidence of osteosarcoma is second only to plasma myeloma. Its histological feature is that tumor cells produce osteoid and immature bone in most cases. Typical osteosarcoma comes from bone, and the other comes from periosteum and nearby connective tissue, which is juxtaposed with bone cortex. The latter is rare, but the prognosis is slightly better.
Three-quarters of this disease occurs between 10-25 years old, and the youngest is 5 years old. Men are twice as many as women.
Tumors mostly occur in the metaphysis of long tubular bones, occasionally in the diaphysis, mostly in the lower femur and upper tibia, accounting for about half of all cases, followed by the upper femur and humerus, and rarely in fibula, pelvis and vertebral body. It is extremely rare for patients with distal limbs (such as hands and feet).
The degree of ossification of osteosarcoma is very inconsistent. In the past, it was often divided into osteolytic and sclerosing, and those with less ossification and rapid growth accompanied by necrosis and cystic degeneration were also called telangiectatic tumors. At present, this title is no longer used. Because the different degree of ossification is only a feature of osteosarcoma, it has nothing to do with the development stage and prognosis of the tumor.
1, lesion
The tumor originated from the bone marrow cavity at the metaphysis of the long tubular shaft. Then it can penetrate cortical bone and uncover periosteum. Perforation of periosteum and soft tissue tumor can also be seen in muscle. Generally speaking, the ossification in the tumor center is more serious than that in the surrounding area. The ossified part is yellow sand. The area with many cells has great toughness and is white. The longitudinal scraping surface of tumor is rich in blood vessels and easy to bleed. The boundary between metaphysis and tumor is not clear. The epiphyseal plate is often inviolable, and the damage of the late epiphyseal plate is lighter than that of the bone cortex. Vitreous cartilage on the articular surface can also prevent tumors from invading the joint. Occasionally, two primary tumors appear at different heights of the same bone, so-called jumping lesions, which should be paid attention to when choosing the amputation plane.
The difficulty of pathological diagnosis varies greatly. If the specimen contains a lot of sarcomatoid matrix, it is not difficult to clearly distinguish tumor bone from osteoid tissue, but there is no tumor osteoid tissue in some sections, only collagen cord, which is surrounded by tumor cells. The only areas where tumor growth is not vigorous are interstitial cells. Some tumors are mainly new cartilage and atypical prismatic cells.
The pathology of osteosarcoma can be divided into four types: the first type is mainly osteoid tissue; Type 2 osteoid tissue and bone tissue coexist; The third type has no bone-like tissue and bone tissue, only collagen fibers; The fourth kind is rare, mainly composed of chondrocytes and tumor cells, with different shapes and poor differentiation. Pathological findings and clinical considerations are valuable. Simple pathological findings can not estimate the growth rate, metastasis mode and survival time of children. Mitosis is a sign of tumor growth rate, but it has little effect on predicting prognosis.
2, diagnosis points
Osteosarcoma is a malignant tumor with sarcomatoid osteoblasts and their osteoid tissues as the main structure, and it is the most common bone malignant tumor. The prone age is 1 1? 20-year-old, male is more than female, the clinical manifestations are mainly pain and local swelling, and the lung is the main metastatic organ, which can be manifested as cough, hemoptysis and chest pain. Clinical diagnosis can be established according to the age, symptoms and signs of patients, combined with X-ray examination and/or CT examination. The final diagnosis must pass histopathological examination. Once osteosarcoma is diagnosed, chest CT examination is the recommended standard examination.
3. Scaffolding
TNM staging of bone tumors (AJCC staging, 6th edition)
T primary tumor.
TX can't evaluate the primary tumor.
No primary tumor was found at T0.
T 1 maximum diameter of tumor ≤8cm.
The largest diameter of T2 tumor is > 8 cm.
T3 has a discontinuous tumor at the primary site.
Local lymph node metastasis.
NX can't evaluate local lymph node metastasis.
N0 has no local lymph node metastasis.
N 1 has local lymph node metastasis.
M transfer from different places.
M0 has no distant metastasis.
M 1 has distant metastasis.
M 1a lung metastasis.
M 1b other distant metastasis.
G pathological grading.
GX could not evaluate the pathological grade.
G 1 highly differentiated.
G2 moderately differentiated.
G3 is poorly differentiated.
G4 is indistinguishable.
Note: Ewing sarcoma and malignant lymphoma are classified as G4.
R residual tumor.
RX was unable to assess the residual tumor status.
R0 has no residual tumor.
R 1 residual tumor under microscope.
R2, the tumor is still naked.
(2) Clinicopathological staging of bone tumors.
M0 first stage A G 1, 2, T 1, N0
M0 T2 N0 Area, Phase I, B G 1, 2
M0 Phase II AG3,4,t1,N0
Phase II B G3, 4, T2, 0, M0
M0 Phase III Arbitrary G, T3, N0
Iva phase is arbitrary g, arbitrary t, N0, m1a.
Ⅳ b period, any g, any t, N 1, any m.
Any g, any t, any n, M 1b
Step 4 deal with
In the past, the only treatment was amputation, which lacked effective chemotherapy drugs. At present, as long as early diagnosis, careful preoperative classification, careful operation and preoperative and postoperative chemotherapy are carried out, the prognosis will be greatly improved. In recent years, the five-year cure rate has been significantly improved. Osteosarcoma should be treated by radical surgery. Conditional cases can be widely excised locally, and limbs can be preserved. In addition, biopsy should be done before amputation to further clarify the clinical and X-ray diagnosis. In order to prevent the tumor from spreading, electrotome can be used.
Principles of treatment
For low-grade malignant osteosarcoma, the main treatment is surgical treatment, while for high-grade malignant osteosarcoma, multidisciplinary combined treatment is needed.
1. High-grade, intramedullary and superficial osteosarcoma: 2-6 cycles of preoperative chemotherapy, including at least the following two drugs: ADM, DDP, IFO and high-dose MTX, and then evaluated. Radiotherapy and chemotherapy were given to patients who could not be resected; Those that can be resected should be extensively resected, including resectable metastatic tumors. If the pathological grade is good, consider chemotherapy; if the pathological grade is poor, consider local radiotherapy and change to chemotherapy. If the margin is negative, the pathological grade is good, the chemotherapy cycle is 2- 12, and the physical therapy and pathological grade are poor, consider changing chemotherapy.
2. Low-grade bone marrow, intracavitary growth+superficial osteosarcoma and paraosseous osteosarcoma: extensive resection, high-grade chemotherapy and re-evaluation after the same follow-up as low-grade osteosarcoma. If it recurs, chemotherapy and reoperation are needed.
13. periosteal osteosarcoma: consider chemotherapy and then extensive resection. Treatment after resection is the same as 2.