Non-ossifying fibroma

Introduction to non-ossifying fibroma Non-ossifying fibroma (NOF) is a rare fibrous tissue tumor. This tumor was once thought to be a tumor-like lesion, the metaphyseal fibrous cortical defect. It was considered a true tumor by Jaffe and Lichtenstein in 1942, and Hatcher considered it to be a metaphyseal fiber defect three years later. Considered to be a tumor-like lesion, Jaffe was officially named as non-ossifying fibroma in 1958. At present, it is considered to be a benign fibrous tissue cell tumor. basic knowledge The proportion of illness: 0.003% Susceptible people: more common in 11 to 20 years old Mode of infection: non-infectious Complications: fracture

Causes of non-ossifying fibroma

Cause (30%):

The cause is unknown. Visual observation, the tumor boundary is clear, biased, solid or tough, the cut surface is yellow or dark brown, composed of yellow and brownish yellow fibrous connective tissue containing lipidoids, and the tumor tissue is mixed with brownish yellow areas, local The cortical bone is thin and swollen, and has obvious boundaries with normal bone. It is surrounded by hardened bone or fibrous bone. The adjacent cortical bone is intact. Unless pathological fracture occurs, if the tumor is composed of multiple lesions, it may be leafy. Generally, there is no periosteal reaction. Under the microscope, the histological features are fusiform fibroblastic hyperplasia, which is arranged in a swirling or mat-like arrangement. There are a small amount of collagen fibers and fibroblasts. The reticular fibers are generally rich, sometimes interstitial. There is hemorrhage and hemosiderin deposition, the latter can be found in spindle cells and multinucleated giant cells. Focal shaped clusters of foam cells are prominent, and phagocytic lipids and hemosiderin-containing tissue cells are transformed by fibroblasts. Foam cells, foam cells appear in 1/3 of cases, but in some cases fibrous tissue and cells are more common, while foam cells are rare, and non-ossifying fibers are degraded. Thickening of collagen bundles, fibroblast-like tumors.

Non-ossifying fibroma 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. The diet includes a variety of vegetables and fruits.

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.

Non-ossifying fibroma complications Complications

Pathological fractures can occur.

Symptoms of non-ossifying fibroma Common symptoms Osteopathic cortical thinning and hardening

The incidence rate is not high, the tumor accounts for 0.81% of the total number of tumors, accounting for 1.45% of benign tumors, the ratio of male to female is 1.38:1, and the age is mostly 11 to 20 years old (29.6%), which is more common in lower limbs, femur and tibia, followed by For the humerus and jaw bones, the upper limbs and short flat bones are less, mostly located at the metaphysis, but do not invade the epiphysis line, or close to the backbone side.

Symptoms are rare, sometimes found after pathological fractures. The main symptoms are local mild pain and tenderness, followed by pathological fractures, which account for about 20% of the first cases. The third case is because of other patients on the X-ray. Unexpectedly, a few were found due to local bone swelling and deformation, and there was no abnormality in the laboratory test.

Examination of non-ossifying fibroma

Check for imaging examinations (X-ray, CT, MRI, etc.), laboratory tests, pathological examinations, etc.

The X-ray features are quite typical, and it is easy to make a diagnosis. The lesion is located on the inner side of the long bone metaphysis. It is 3~4cm away from the tarsal plate. The latter is not involved. The lesions vary in size from 1 to 5cm, and some can reach 10cm. Shape or elliptical, eccentric growth, consistent with the long axis of the bone, but tends to invade the entire bone, the lesion is often lobulated inside, the cortical bone is thin, and the medullary margin is hardened, the boundary is clear, located in the cortical bone In the vicinity, the bone is protruded from one side, the surface bone is slightly expanded, and the bone is thinned. It can be eccentrically grown in the thick bone such as the femur. The small bones such as the tibia can fill the medullary cavity, and the surface bone changes slightly. Thin, the bone at the border of the tumor and the medullary cavity is slightly hardened, often in the form of a soap foam, which can be combined with pathological fractures.

Diagnosis and identification of non-ossifying fibroma

diagnosis

Occurred in adolescents, clinical symptoms are not obvious, combined with X-ray characteristics should consider the disease, to determine the diagnosis requires pathological examination, the disease is relatively rare, clinicians and radiologists are more difficult to make a correct diagnosis, many authors report preoperative diagnosis mistaken.

Some authors have included a large number of fibrous cortical bone defects in this disease. Non-ossifying fibroma and fibrous cortical bone defects have the same histological appearance, so many authors regard the two as a disease, and consider it as a fibrous cortical bone. Defective lesions are converted to non-ossifying fibroids after the cortical expansion invades the medullary cavity and causes destruction of the medullary cavity. However, most scholars hold the opposite opinion and believe that the differences are as follows:

The difference between non-ossifying fibroma and fibrous cortical bone defect:

Non-ossifying fibroma fibrous cortical bone defect lesions The incidence of primary benign bone tumor-like lesions is low, accounting for about 1% of bone tumors, showing 27-40% of normal children, with family-oriented age of onset More common in 15 to 20 years old, more common in 5 to 14 years old, clinical symptoms often have masses and pathological fractures, more asymptomatic expansion trend, progressive expansion, large lesions, can not self-heal, there may be occasional recurrence, 2~ Within 4 years, it disappeared on its own, and it can appear again. The disappearing X-ray showed more single lesions, and the long diameter was more than 6cm. The single or multi-layer swelling density was reduced. The cortical bone was thin but the lesions were multiple and symmetrical. Single hair, long diameter more than 4cm, cystic or flaky bone defect, no obvious swelling, obvious cortical bone defect.

Differential diagnosis

1, single fibrosis dysplasia: especially vesicular changes are rare, often in the proximal tubular dry metaplasia, no obvious clinical symptoms, often with pathological fractures, X-ray findings of intramedullary localized osteolytic Bone destruction, frosted glass, which can be seen in irregular trabecular bone or calcification, no obvious bone sclerosis at the edge, fibrous tissue and metaplastic bone under the microscope.

2, giant cell tumor of bone: older, more common in the long tubular epiphysis, the symptoms are obvious, X-ray eccentric swelled osteolytic destruction, the boundary is unclear, soapy foamy or osteolytic translucent area change, microscope See stromal cells and multinucleated giant cells.

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