Osteoid osteoma

Introduction to osteoid osteoma Osteoarthritis was first reported by Jaffe in 1935 and is a benign osteogenic disorder with osteoid osteopathy. Its incidence accounts for 2% to 3% of bone tumors, mostly in long tubular bones, about 50% to 60% occur in the femur and tibia, and a few occur in other bones of the body. The diameter of the tumor generally does not exceed 1.5cm, close to 2/ 3 cases with persistent pain as the main symptom, with a clear focal lesion, surrounded by a larger bone reaction area. Salicylic acid preparation can relieve pain. The disease is a common bone tumor with characteristics. basic knowledge The proportion of illness: 0.03% Susceptible people: no specific population Mode of infection: non-infectious Complications: swelling, torticollis

Cause of osteoid osteoma

(1) Causes of the disease

The cause is not completely affirmed, but some scholars believe that the disease is a primary benign tumor, based on:

1 growth is slow;

2 bone-like tissue replaces normal tissue;

3 surrounding bone tissue exhibits uniform structural hardening without exception;

4 The size is fixed and the above arguments are widely recognized.

Other scholars believe that it is inflammation, but may be related to viral infection, and some are considered to be vascular sources or related to arteriovenous dysplasia, or compensation process.

(two) pathogenesis

1. Gross examination In the intact specimen, the tumor and the surrounding bone tissue are clearly demarcated, round or elliptical, small in size, generally about 1 cm in diameter, rarely more than 2 cm, and the surrounding tissue is reactively hardened, and the tumor is located in it. Center, the color and firmness of the tumor vary with its composition. When the bone-like tissue predominates, the core is brownish red, with yellow or white spots interspersed, and the texture is granular or gravel. X-ray examination is one. The transparent area, when the core is composed of dense trabeculae, is reddish white, the texture is hard and dense, the X-ray is a density deepening area, and the tumor has a narrow, ring-shaped congestive zone separated from the surrounding bone tissue. Bone tissue generally has reactive osteosclerosis, especially in tumors that occur in the cortical bone.

2. Microscopic examination of bone-like osteoma in the nest can have different mature stages of bone, and is rich in vascular connective tissue matrix, with different proportions of bone-like tissue and new bone trabeculae, when the core is dense and solid in the visual inspection At the time of the microscope, there are closely arranged atypical new trabecular bones with enlarged sinusoids between the trabeculae. The newly formed trabecular bone is covered by osteoblasts, and there are often a few osteoclasts.

Osteoid osteoma prevention

The current cause of the disease is not very clear, there is no effective preventive measures, but the clinical attention should be paid to the possibility of deterioration of the disease, although it is rare, for some patients with typical osteoid osteoma imaging findings, if observed To the discontinuity of the cortical bone and the surrounding soft tissue mass, the possibility of malignant transformation of osteoid osteoma should be considered.

In addition, it should be noted that this disease is more likely to be misdiagnosed. Most patients can not immediately return to the clinic after symptomatic treatment, and they can take medicine at home, making the disease repeated and the clinical symptoms are atypical, which is more likely to cause misdiagnosis. Therefore, the suspected patient should be detailed. Asking about the medical history and carefully observing the results of the X-ray examination will help to make a better diagnosis and give the right treatment.

Osteosarcoma complications Complications swelling and torticollis

As the disease progresses, the pain gradually becomes persistent severe pain, especially at night, which is quite characteristic. It is reported in the literature that osteoid osteoma occurs at the end of the bone or irregular bones such as the femoral neck, vertebrae, etc. Osteosclerosis is not obvious or only a thin hardening ring, is a cancellous bone type, some patients may have osteoid osteoma worsening, the signs of malignant transformation are mainly local cortical destruction, discontinuous, visible soft tissue density mass around the lesion And swelling, especially soft tissue changes may suggest signs of malignant transformation, such as osteoid osteoma in the spine bone can appear torticollis, scoliosis.

Osteoarticular osteoma symptoms Common symptoms Osteopathic persistent pain dull pain Soft tissue swelling Muscular atrophy Scoliosis sacral cyst

The disease is most common in 10 to 30 years old, but it can also be seen in infants under 1 year old or older than 60 years old. Men are more common than women, the incidence rate is 2:1, and the incidence of lower limbs is about 3 times that of upper limbs. It is rare in the trunk bone, and the tibia and femur are the most common, accounting for about half of the cases, followed by the humerus, the tibia and the spine.

The course of the disease is characteristic, the pain appears earlier, and it often exists in the first few months after the positive lesion on the X-ray film. The disease is intermittent pain at the beginning of the disease, the nighttime is aggravated, the painkiller can be relieved, and the pain is aggravated in the later stage. Sex, any medicine can not relieve it, pain is limited, soft tissue can be swollen, but the affected area is few, some patients can also have no pain symptoms, when the lesion is small, the pain can be accompanied by vasomotor reaction such as increased skin temperature and more Sweat, pain is not necessarily limited to the affected area but can also be radiated to nearby joints.

The size of osteoid osteoma is another feature of this lesion. Some people have a size of 1 cm, but it has also been reported to be 1.5 cm. In short, the volume is small.

Pain is the main symptom. If there is no pain, the diagnosis is doubtful. The pain is characterized by intense nighttime. When taking a small amount of salicylic acid, the pain can be relieved. The nature of the pain is often dull or stinging, and it starts to be mild. It is intermittent, so it takes several months to several years to see a doctor. After that, the pain is aggravated and becomes persistent. It may also be accompanied by local soft tissue swelling or tenderness. The mechanism of pain is still unclear. Some people think that it is produced in tumor tissue. The prostaglandin product can cause changes in vascular pressure that stimulate local nerve endings, a perception that is supported by the presence of unmyelinated nerve fibers in the surrounding fibrous band of the diseased core or in the core itself.

Other clinical manifestations of osteoid osteoma may be related to the age of onset of the patient and the part of the bone that is invaded. When the bone is immature, muscle atrophy and skeletal deformity may occur. For example, the osteoarthritis may be located on the spine bone. Stiffness, scoliosis, and osteoid osteoma located in the joint may have local tenderness of the joint, swelling of the synovial membrane, limited mobility, etc. Osteoid osteoma may have various clinical manifestations, but laboratory tests are generally normal.

Examination of osteoid osteoma

Laboratory tests are generally normal.

1. X-ray examination typical X-ray manifestation: an elliptical or circular central X-ray transparent area of diameter <1cm, surrounded by a uniform hardening band, is not actually so typical, the spine The carpal bone, the osteoid osteoma of the foot and the osteoid osteoma of the long tubular bone may be different, and the lesion may occur in the diaphysis, medullary cavity or cancellous bone, or under the periosteum, resulting in different X-ray signs, there are more than one lesion in a few cases, but many lesions can be different from the above description, and there is no evidence that it is related to the onset and the disease stage. It can be combined with chronic bone abscess, acute or chronic bone marrow by angiography. Inflammation, isolated endogenous osteophytes, aseptic necrosis, osteochondritis identification, although osteomyelitis is hyperemia, but the vascular morphology is normal or slightly dilated, there is no redness of osteoid osteoma, bone abscess and sterility The necrotic center of sexual necrosis appears as avascular area.

(1) long tubular bone: osteoid osteoma located in the long tubular bone often occurs on the backbone, there is a radioactive transparent shadow in the cortical bone, this shadow is called a nest, the nest can have different degrees of calcification, around the nest It is surrounded by hardened bone and accompanied by thickening of the cortical bone (Fig. 2). This is due to the formation of new bone in the subperiosteal and periosteum. In the rare case, there may be several osteoid osteomas in the same bone. Each osteoid osteoma has its own nest. The response zone of the hardened zone around the osteoid osteoma is different. Sometimes the nest can be completely filled, whether the nest exists and its shape should be further examined by X-ray or CT. To determine, the osteoid osteoma in the neck of the femur often occurs on the inner side of the femoral neck. The nest is located in the subperiosteal or cortical bone. Under normal circumstances, the medial cortex of the femoral neck is thicker, so if there is mild cortical bone enlargement Thickness often makes diagnosis difficult, and in the area where the cortical bone is thickened and there is a light-transmitting area, attention should be paid to the identification of stress fractures.

(2) Wrist, humerus and callus: Osteoid osteoma in the epiphysis of the wrist, humerus and long tubular bone often occur in the cancellous bone, and the X-ray shows a partial or all calcified circular lesion. There is a lack of reactive osteosclerosis around it. This performance is completely different from that of osteomyelitis on the cortical bone. It is difficult to diagnose. For example, if the bone is not mature in children, osteoid osteoma can cause bone development malformation.

(3) small bones in the hands and feet: in the palm, sac, or osteoid osteoma in the phalanx, such as in the cortical bone, the performance is the same as that seen in the long tubular bone. If it is located under the periosteum, the surrounding cortical bone is visible. "Scallop" changes, in the hand, osteoid osteoma of the small bone of the foot is often accompanied by soft tissue swelling.

(4) In the joint: If the osteoid osteoma occurs in the joint, it can cause pain, soft tissue swelling, joint effusion and joint movement limitation, often misdiagnosed as joint disease, special attention should be paid during the examination.

(5) Spinal column: Due to the complex anatomy of the spine, the bone on the common X-ray film is often blocked by the surrounding soft tissue, and the clinical manifestations can have different symptoms. Therefore, the diagnosis of osteoid osteoma in the spine is very difficult, and its clinical manifestations are often Severe radiation pain, increased at night or when the spine is active, most patients have scoliosis, which is called painful scoliosis. Therefore, when scoliosis is accompanied by obvious pain, it is often considered to be the upper spine. The important clinical manifestations of osteosarcoma, of course, this symptom is not unique to spinal osteoid osteoma. The osteoid osteoma on the cervical vertebra can be oblique to the neck. The osteoid osteoma on the spine has few neurological symptoms.

The osteoid osteoma on the spine is characterized by a concave side on the scoliosis of the spine, close to the apex of the lateral curve, which can be seen in the pedicle, lamina, articular process, and occasionally a hardened area on the transverse process, in the ordinary X-ray It is very difficult to find a radiation-clear nest on the film. It is necessary to use the help of a tomography or CT examination. It should be emphasized that if a sclerosing bone lesion is found on the posterior structure of the spine, it is an important sign for the diagnosis of osteoid osteoma, but bone metastases, Infection, spondylitis, etc. can also have this manifestation, should pay attention to differential diagnosis.

(a) Cortical osteoid osteoma:

There is a small transmission line area, surrounded by dense bone, the lesion is located in the cortex, the hardening ring is more obvious, the periosteal reaction is layered or substantially homologous, and in the late stage of the disease, the lesion can be completely concealed.

(2) Cancellous osteoid osteoma:

The most common in the femoral neck, followed by the small bones and vertebral bodies of the hands and feet, there is often no new bone formation around the lesion, but the increased density of the bone ring around the lesion, occasionally in the distant occurrence of reactive new bone formation.

(c) subperiosteal osteoid osteoma:

Usually expressed as a soft tissue mass near the bone, most commonly in the inner surface of the femoral neck and the hands and feet, the bone directly below the lesion has a fan-shaped area, caused by compression atrophy or bone resorption, when the lesion is close to the joint, non-reactive bone formation However, there may be joint swelling, congestion and pain, which is characterized by acute synovitis. There is no other change in the bone at both ends of the joint except for obvious decalcification. There is evidence that the disease can naturally resolve, but it takes a long time.

2. Radionuclide scanning and gamma scintigraphy in patients with osteoid osteoma for preoperative radionuclide scanning and gamma scintigraphy should be used as a routine examination, for osteoid osteoma in the spine, due to inaccurate X-ray diagnosis, and radionuclide scanning The lesions are sensitive and reliable, and the use of radionuclide scanning can cause double-density signs of osteoid osteoma: that is, the scintillation activity in the lamina of osteoid osteoma is enhanced, while the radionuclide concentration in the surrounding hardening area is less. It is helpful for the diagnosis of osteoid osteoma.

3.CT General osteoid osteoma can be diagnosed by ordinary tomography. It is of great value in the diagnosis of special parts such as spine, pelvis and femoral neck. Thin-slice CT scan is the best method to show osteoid osteoma. X-ray film and MRI can more accurately display the tumor nest, and can diagnose suspicious cases that cannot be diagnosed on the plain film, especially for the joints with complex anatomical structures such as the joint capsule and the spine.

Diagnosis and differentiation of osteoid osteoma

diagnosis

Through clinical manifestations, histology and radiology can establish a diagnosis, long course of disease, local persistent pain and tenderness, X-ray films with thickened cortical bones, or hardened bone around the cancellous bone. Osteosarcoma should be considered in patients with localized bone-transparent areas or localized bone destruction. CT examination and angiography may contribute to the location of the tumor nest.

Differential diagnosis

Osteoid osteoma has special pain symptoms and typical X-ray of the tumor nest, which is easier to diagnose, but it still needs to be differentiated from the following bone diseases.

(1) Chronic bone abscess is a low-grade chronic suppurative infection with inflammatory symptoms such as redness, swelling, heat and pain, and has a history of recurrent episodes. It occurs in the metaphysis of the long bones, the destruction area is large, and the cortical bone is damaged. The surrounding is dense, sometimes with small dead bones, but no tumor nest, X-ray film shows localized defects of cortical bone, surrounding bone is dense, there may be small dead bone formation, intraoperative bone cavity contains pus, granulation Tissue, microscopic observation of a large number of multinucleated white blood cells and lymphocyte infiltration.

(2) Chronic sclerosing osteomyelitis (Ga rre type) pain properties similar to osteoid osteoma, often intermittent, X-ray manifestations: bone limitation or extensive hyperplasia, no tumor nest, medullary stenosis or even occlusion.

(3) Osteoblastoma: Both are benign osteocytic tumors, osteoblastic tumors have no local pain at the end of the bone, but the development is faster, the destruction area is larger, often > 2 cm, the cortical swelling is obvious. Hardening around.

(4) Single endogenous osteophytes have no peripheral bone sclerosis, no pain, and often occur in small bones of the hands and feet.

(5) Stress fracture: one side of the cortical bone fracture, localized periosteal hyperplasia, osteosclerosis, resembling osteoid osteoma, but the transverse or fracture line of the body layer or MRI can be seen, and there is a long history of continuous movement.

(6) Bovespot or Bone island, the brush-like edge of the lesion is mixed with the surrounding trabecular bone, and the expression is "radiation-like" or "pseudo-foot", X-ray film See the limited circular and oval bone density in the bone to increase the shadow, without hardening shadows around, without any clinical symptoms.

It is worth noting that in histological examination, osteoid osteoma is very similar to osteoblastoma. It should be differentiated according to the size, location and clinical manifestations of the tumor. It is generally asymptomatic and requires no treatment.

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