Osteoblastoma

Introduction to osteoblastoma Osteoblastoma is a rare type of tumor that has been benign in the past in order to distinguish it from osteosarcoma so as not to confuse the two. Its histological features are: bone-like bone Tumor, but its outcome is different from osteoid osteoma. In fact, the tumor is histologically non-malignant, but often invasive, and even lung metastasis or malignant transformation. In the past, due to different opinions and starting points, the name of the tumor was more confusing, such as benign osteoblastoma, giant osteoid osteoma, benign osteoblastoma. The above naming has its limitations, so the name of osteoblastoma is now unified. In order to avoid misunderstanding, it is better not to be "benign", and at the same time to be classified as a primary tumor with a tendency to be malignant. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: spinal cord compression osteosarcoma

Osteoblastoma etiology

Viral infection (20%):

In 1932, Jaffe first reported a case of "a tumor formed by the osteoblastic bone-like tissue of the metacarpal bone", which is considered to be an independent clinical condition, but its true cause has not yet been clarified. Benign tumors of osteogenesis connective tissue, some scholars believe that the tumor is a response to non-suppurative infections, but also believe that it is by no means a general infection, and may be related to viral infection.

Vascular abnormalities (5%):

Recently, some scholars have found vascular dysplasia in patients with osteoblastoma by angiography, so it is believed that the occurrence of osteoblastoma is related to vascular abnormalities.

Pathogenesis

In long tubular bones, the maximum diameter of osteoblastoma can range from 2 to 13.5 cm. The erosion of the tumor can swell the cortical bone. The outer edge of the tumor is often surrounded by a periosteum and a thin layer of hardened bone. In the short bone, the lesion may expand in a fusiform shape, and the osteoblastoma at the spine may expand into the epidural space.

When the tumor is dissected, it can be seen that the medullary cavity of the tumor has a thin bony margin. The tumor tissue may be gravel-like, gray-brown or brown-red or granulated tissue, and occasionally may be accompanied by a soft cystic region.

The basic pathological features of osteoblastoma are similar to those of osteoid osteoma, including connective tissue matrix with abundant blood vessels, active bone-like tissue and primitive reticular bone in the matrix, and the types under the microscope vary greatly. In mature lesions, there is a large amount of connective tissue. There are polymorphonuclear osteoclasts and small bone-like lesions in the matrix. In mature tumors, the bone-like tissue has progressive salt deposition and is transformed into a disordered arrangement. The reticular trabecular bone is rich and active in the trabecular bone. Although the osteoblast is rich, the cells and nucleus are generally not atypical, and nuclear fission is occasionally seen.

Osteoblastoma prevention

There are no special and effective preventive measures, and some adjustments can be made in the diet:

1. Maintain an ideal weight;

2. Ingest a variety of foods;

3. A variety of vegetables and fruits are included in the diet each day;

4. Ingest more high-fiber foods (such as whole grain cereals, beans, vegetables, and fruits);

5. Reduce total fat intake;

6. Limit the intake of alcoholic beverages;

7. Limit the intake of marinated, smoked, and nitrite-containing foods.

Osteoblastic complications Complications spinal cord compression osteosarcoma

Can be complicated by spinal cord compression symptoms and radioactive root pain, can also be complicated by osteomalacia, multiple recurrences can become osteosarcoma.

Osteoblastoma Symptoms Common Symptoms Osteopathic Bone Destruction Spinal Cord Compression Long Bone Swelling Pain

1. The tumor is not too common, accounting for about 1% of the total number of bone tumors, the ratio of male to female is 2:1, the patient's age is 80% less than 30 years old, and the age of 25 is the peak incidence.

2. The incidence of the spine is relatively high, accounting for 41% to 50%, half of which occurs in the lumbar vertebrae, followed by the thoracic vertebrae, cervical vertebrae and atlas. The lesions on the vertebrae are mostly located behind the spine, especially the pedicles are susceptible first.

3. Early local pain and root radiation pain, no more pain at night, but not sensitive to aspirin response.

4. Neurological symptoms: Corresponding neurological symptoms appear according to the plane of the affected spine. Tumors of the lumbar spine can cause radiating pain in the lower leg, accompanied by lumbar muscle spasm. Tumors of the cervical or thoracic vertebrae may have weakness and numbness in the upper and/or lower limbs, and even complete motor impairment. Tumors of the tibia can also cause compression symptoms of nerve roots.

Examination of osteoblastoma

Laboratory examination: laboratory examination is basically normal, individual cases have increased erythrocyte sedimentation rate, and CSF does not change much. If the tumor turns to malignant, serum alkaline phosphatase (AKP) will increase.

Film degree exam:

X-ray findings: The tumor showed a change in osteolytic swelling, the boundary was clear, and the cortical bone outside the lesion became thin. Depending on the degree of calcification and vascular richness, either plaque calcification or a large translucent area. If the lesion spreads to one side of the cortex, it can be broken, so that the tumor invades the spinal canal or surrounding soft tissue.

CT findings: The main features are expansive soft tissue density bone destruction, high-density hardening margins of varying thickness and varying degrees of calcification and ossification.

MRI findings: no calcified ossification lesions, moderate signal on T1WI and high signal on T2WI. After calcification or ossification of the lesion, both T1WI and T2WI may have spotted, cord-like, agglomerate or irregular low-signal regions. As the calcification ossification progresses, the range of the low signal region can gradually increase. The hardening margins around the lesions showed a low signal loop on both T1WI and T2WI. The lesion is adjacent to the congested edema area of the medullary cavity and soft tissue. Generally, the periosteal reaction is not obvious, the surrounding soft tissue may be slightly swollen, and the soft tissue mass is mostly not obvious. Enhanced scanning showed that the bone-like tissue was abundantly enhanced, and the adjacent medullary cavity and soft tissue were slightly strengthened, while the lesions were not enhanced by calcification, cystic changes and hemorrhage.

Diagnosis and diagnosis of osteoblastoma

diagnosis method:

1. The disease is more common in young people, about 41% to 50% are located in the spine, and the pedicle is susceptible to being affected first.

2. The root symptoms appear earlier, and the remaining neurological symptoms vary depending on the affected plane.

3. X-ray sees bone destruction with clear boundaries and varying sizes, and has varying degrees of ossification, and the marginal bones expand and become thinner.

4. Pathological examination showed a large number of osteoblasts, bone-like tissues and vascular fibrous tissues in the tumor tissue.

Differential diagnosis:

If there is a certain difficulty in identifying from X-ray films, the differential diagnosis depends mainly on pathological examination. Tumors that are easily confused with osteoblastoma include osteoid osteoma, osteosarcoma, giant cell tumor of bone, poor fibrous structure of the bone, aneurysmal bone cyst and hemangioma.

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