Broadly speaking, any bone overgrowth, whether tumor or not, can be called osteoma. But the real osteoma should only refer to the tumor of endoskeleton, excluding the ossifying fibroma caused by excessive proliferation, hematoma organization, calcification or inflammation and trauma.
Osteoma is more common than osteochondroma. Osteoblasts that occur in periosteum lining. It is a benign tumor, which is composed of osteoblasts, osteoblasts and new bone, and grows with growth.
I. Clinical manifestations
The incidence rate is second only to osteochondroma, which is more common in children and more common in men. Growth is slow and symptoms are mild. There is no trend of malignant transformation.
Most of them occur in skull and facial bones, and occasionally in mandible, which are divided into dense osteomas and cancellous osteomas.
Dense osteoma occurs on the craniofacial bone surface, local uplift, and occurs on the intracranial plate. If the tumor invades, it can cause intracranial compression, dizziness, headache and even epilepsy (Figure 2- 1).
Osteosarcoma usually occurs in the cartilage at the junction of the long bone shaft and epiphysis. With the increase of tubular bone length, osteoma also changes and presents different shapes (Figure 2-2).
Generally, the whole body bones stop growing when they are mature. However, in the development process, if osteoma causes bone compression, it can still cause abnormal growth (Figure 2-3).
Osteoma occasionally occurs in soft tissue, but it is considered as a hamartoma, not a real osteoma.
Second, the image diagnosis
Dense osteoma is characterized by protrusion, smooth external ratio and broad and wavy base of skull osteoma. If it is located on the inner plate, the inner plate becomes thicker. The bone density increases evenly, and the degree of bone destruction and ossification is often inconsistent.
Osteowarts are often pedicled, and cartilage can be calcified, showing cauliflower shape. (Figure 2-4)
Three. pathological change
Osteoma is hard and covered by periosteum, and its base is connected with bone tissue, which may have a wider base or pedicle. The slice is bone tissue.
According to the different bone density, it can be divided into ivory bone type (dense bone type) and sponge bone type (cancellous bone type), the former is more common. Microscopically, the structure is simple, which may contain bone plate and a little Harrington tube, and cancellous bone type may have bone marrow tissue.
Fourth, diagnosis and differential diagnosis
(1) Osteomas occurring in paranasal sinuses are more common in frontal sinus and ethmoid sinus. They are usually lobulated, pedicled, with neat edges and uniform density. When you grow up, you can occupy the sinus cavity and even push up the sinus wall, resulting in frontal bone deformity. General diagnosis is not difficult.
(2) It should be differentiated from meningioma, hyperplasia of inner plate of frontal bone and fibrous dysplasia.
1. Meningiomas grow rapidly, showing non-plastic new bone hyperplasia and osteoid changes. The tumor base is wide, and the skull plate may have osteolytic changes. The increase of blood supply of tumor leads to the widening and enlargement of the shadow of vascular sulcus nearby. Orbital ethmoidal sinus osteoma is sometimes difficult to distinguish from olfactory groove meningioma.
2. The medial plate of frontal bone hyperplasia is wavy bone hyperplasia, and patients often have symptoms such as headache, obesity and decreased libido. More common in postmenopausal women, sometimes accompanied by diabetes or diabetes insipidus.
3. Fibrodysplasia of skull has a wide range of lesions and a wide base, and many diseases involve lamina and skull plate. Other bones in the whole body can also be involved and have a unilateral tendency.
(3) It should be differentiated from osteochondroma and osteosarcoma.
1. Exogenous bone warts, such as whole-body bones, are osteomas, and some are called osteochondromas, which contain cartilage calcification. It is difficult to tell the difference between the two, depending on the disease examination.
2. Endogenous muscular wart, also called bone spot or bone island, is an abnormal bone development in cancellous bone, which is nested and may have trabecula. It's not a tumor
3. Osteosarcoma grows rapidly and has the characteristics of malignant bone tumor, so it is easy to distinguish whether it is prone to age and location.
Verb (abbreviation of verb) processing
Osteoma develops slowly, and asymptomatic patients are largely undetected and usually do not need treatment. However, if it grows rapidly, it has caused benign deformity or compression symptoms, or it continues to grow after adulthood, it can be surgically removed.