Bone tumors are tumors that occur in the bone or its appendages. Benign bone tumors are easily curable and have a good prognosis, while malignant bone tumors develop rapidly and have a poor prognosis and high mortality. Malignant bone tumors are divided into primary and secondary. Malignant tumors from other tissues or organs in the body metastasized to bone through blood circulation and lymphatic system are secondary malignant bone tumors. There is another category of lesions called tumor-like lesions. The tissues of tumor-like lesions do not have the characteristics of tumor cell morphology, but their ecology and behavior have the destructive nature of tumors, which are generally more limited and easily curable.
I. Etiology
The factors of bone tumors are complex, and there is no exact etiology yet. The internal causes include quality theory, genetic theory, endocrine theory, etc.; the external causes include chemical element substance and chronic stimulation theory of internal and external irradiation, viral infection theory, etc. Some of the multiple osteochondromas and fibrous proliferative disorders are related to family inheritance. Benign tumors of bone can become malignant: for example, multiple osteochondroma can become chondrosarcoma.
Clinical manifestations
1.Pain
It is the main symptom of bone tumor in early stage, which is mild and intermittent at the beginning of the disease, but with the progress of the disease, the pain can gradually increase and develop into persistent. Most of the patients’ pain increases at night and affects their sleep. The pain can be radiated to distant places.
2.Swelling or lump
Tumors located under the periosteum or superficially appear earlier, and the bone can be swollen and deformed by touch. If the tumor penetrates outside the bone, it may produce a fixed soft tissue mass with smooth or uneven surface.
3.Dysfunction
In the late stage of bone tumor, the function of the affected part will be impaired due to pain and swelling, which may be accompanied by muscle atrophy of the corresponding part.
4.Compression symptoms
Tumor growing into the cranial cavity and nasal cavity may compress the brain and nasal tissues, thus causing cranio-cerebral pressure and respiratory symptoms; pelvic tumor may compress the rectum and bladder, resulting in difficulty in defecation and urination; spinal tumor may compress the spinal cord and cause paralysis.
5.Deformity
The tumor affects the development and sturdiness of limb bones, and the deformity is obvious in lower limbs.
6.Pathological fracture
Pathological fracture of spine is often combined with paraplegia.
7.Systemic symptoms
Due to the consumption of tumor, stimulation of toxin and pain, a series of systemic symptoms may appear in the late stage of bone tumor, such as insomnia, irritability, loss of appetite, depression, pallor, progressive wasting, anemia, cachexia, etc.
III. Examination
1.Radiological examination
It is an important examination method for bone tumor, which can provide valuable information to clarify the nature, type and scope of bone tumor and decide the treatment policy. Benign bone tumor has regular morphology, clear boundary with surrounding normal bone tissue, bounded by sclerotic edge, bone cortex thins due to expansion, but still remains intact without periosteal reaction, while malignant tumor has irregular image, blurred edge, osteolysis phenomenon is more obvious, bone destruction, thinning, fracture, missing. The shape can be sunburst, onion skin and Codman triangle.
2.Pathological examination
Pathological histological examination is considered to be a diagnostic method with the highest accuracy, but improper extraction of material can cause diagnostic errors, so pathological examination must be combined with clinical and x-ray examination. The commonly used methods of sampling and examination include needle aspiration biopsy, incisional biopsy, frozen section, paraffin section, etc.
3.Radionuclide examination
It can be used for the early diagnosis of bone metastases.
4.CT and magnetic resonance
It can detect the diseased tissues at an early stage with high accuracy.
5.Other
Blood sedimentation is accelerated in osteosarcoma, and alkaline phosphatase may be increased in osteogenic metastatic bone tumors.
Diagnosis
The diagnosis of most bone tumors is complicated and sometimes difficult because different bone tumors can have similar manifestations and benign bone tumors can become malignant; some bone tumors show benign differentiation on histological examination but are highly malignant clinically and often have pulmonary metastases at an early stage. Therefore, a comprehensive analysis should be made by combining all the above examinations, and the final diagnosis depends on histopathological examination.
V. Treatment
1.Benign tumor
Mostly local scraping and bone grafting or resection is the main treatment, if it can be completely removed, generally no recurrence and good healing.
2.Malignant tumor
(1) Surgical resection is the main means of treatment. Amputation and joint severance are the most common methods. However, due to the progress of chemotherapy, some scholars have started to make resection of tumor segment or total femoral resection and replace it with artificial prosthesis in recent years. We also take measures such as “extensive local excision plus functional reconstruction” with chemotherapy to preserve the limb.
(2) Chemotherapy systemic chemotherapy includes Adriamycin and high-dose methotrexate, but the selective action of the drugs and the unsynchronized tumor cells in the division cycle affect the effect of chemotherapy.
(3) Local chemotherapy includes intra-arterial continuous chemotherapy and regional perfusion, among which regional perfusion is more effective.
(4) Immunotherapy cannot be widely applied due to the limited source of interferon.
(5) Radiotherapy can only be used as an adjuvant treatment for bone tumors.