Osteogenic fibroma, also known as osteogenic fibroma and osteogenic fibroma, accounts for 0.7% of primary bone tumors and 1.2% of benign bone tumors. The age of onset is from 8 months to 20 years old, and 50% is less than 5 years old. The age of onset is between 8 months and 20 years old, and 50% of them are less than 5 years old, and there are more females with a male to female ratio of 1:3. The site of onset is mostly in the tibia, followed by the femur, humerus, ulna and radius.
Clinical manifestations
The tumor grows slowly, and the duration of the disease varies, up to several years, generally asymptomatic. The onset of the tibia is mostly in the anterior cortical part of the backbone, and the tibia is often seen to have an anterior arch deformity.
Auxiliary examination
1.X-ray examination: the lesion occurs in the cortical bone on the side of the diaphysis or near the epiphysis, without involving the epiphysis, and the lesion is eccentrically distended, mostly irregularly unicystic or multicystic in shape, with clear contours and hardened edges. If the lesion is extensive, it may cause obvious deformity of the affected bone.
2.CT examination: cystic destruction in the bone cortex is seen, and there are often irregular high-density areas caused by hyperplasia and ossification between them. The CT value of the sclerotic osteogenic area varies from 500 to 1400 Hu, and the bone cortex is irregularly thickened and protrudes into the medullary cavity, resulting in deformation and shrinkage of the medullary cavity, and sometimes the medullary cavity can be occluded.
3.MRI examination: Most of the lesions are low signal on T1-weighted image and T2-weighted image, and sometimes they may show high signal on T2-weighted image.
4.Pathological examination: The bulk specimen seen by the naked eye is grayish or grayish-pink in color with gravelly feeling. Due to more fibrous components, it is similar to fibroma. Surgically, the tumor was seen to be locally elevated and the cystic lesion was greenish-purple in color, containing yellow liquid and granulation-like tissue.
Microscopically, the tumor was composed of fibrous tissue and bone trabeculae. Fibroblasts and fibroblasts are amorphously arranged and form collagen fibers. Bone trabeculae are evenly distributed in the fibrous connective tissue with irregular shape and surrounded by rows of osteoblasts, occasionally osteoclasts can be seen.
Diagnostic points
1. The main manifestation is local pain and mass. The mass has light pressure pain, or it is painless. The lesions in the adjacent joints have functional impairment.
2.X-ray shows that the lesion area is a cystic hypodensity area, which can be single or multi-cystic. In advanced stage, the tumor tissue gradually ossifies and the density increases, but the surrounding area can still be a hypodensity area.
3.Microscopic examination shows amorphous arrangement of fibroblasts and fibroblasts, and scattered bone trabeculae within the fibrous stroma, with irregular morphology and surrounded by a single layer of neat osteoblasts.
Differential diagnosis
1. The main differentiating point of osteochondrodysplasia is that the lesion of osteochondrodysplasia is located in the bone marrow cavity, with central expansion and unclear borders, and the X-ray shows frosted glass-like changes. In contrast, in fibrodysplasia, the bone trabeculae are only matured to the stage of woven bone, and no plate-like bone can be seen, while immature bone trabeculae are surrounded by fibrous tissue without osteoblast coverage.
The main differentiation point of giant cell tumor of bone is that the lesion of ossifying fibroma mostly involves the bone stem and does not go beyond the epiphysis, and the lesion area is a cystic hypodensity zone, which can be single or multiple cysts. In contrast, giant cell tumor of bone is located at the epiphyseal closure, and there is no ossification shadow in the lesion. Pathological examination is easy to distinguish.
The main differentiation point of osteoblastoma is that the location of ossifying fibroma is the epiphysis or bone stem, not beyond the epiphysis, and the lesion area is a cystic hypodense area. In contrast, osteoblastoma shows small round hypodense shadows in the epiphysis with clear borders, surrounded by reactive bone to form a sclerotic margin, and punctate calcification is visible in the lesion. Pathological examination is easy to differentiate.
Treatment and rehabilitation
1.Non-surgical treatment: osteoblastic fibroma in childhood may be left inoperative and reviewed regularly.
2.Surgical treatment: scraping and bone grafting: when the tumor is small, scraping and bone grafting can be done, but such cases are less. After scraping the tumor, the tumor cavity is completely inactivated. 95% ethanol, carbolic acid and liquid nitrogen can be applied, and after scraping, autologous bone, allogeneic bone or artificial bone can be used to fill the tumor cavity, and for those who are invasive, bone cement filling can be considered.