Osteochondromas or osteocartilaginous exostoses are the most common benign tumors in bone. The tumor takes the form of bones that are covered in bone projection or growth on the surface of the eksostosis bone. It is characterized as the type of overgrowth that can occur in any bone where cartilage forms the bone. Tumors most commonly affect long bones about the knees and forearms. In addition, flat bones such as the pelvis and scapula (scapula) may be affected. Typhoon exposure is usually present during childhood. However, most affected individuals become manifested clinically by the time they reach their teens. Osteochondromas occur in 3% of the general population and represent 35% of all benign tumors and 8% of all bone tumors. The majority of these tumors are solitary non-heritative lesions and about 15% of osteochondromes occur as Histitary multiple exostoses, better known as hereditary multiple osteochondromas (HMOs). Osteochondromas is not the result of injury and the exact cause is still unknown. Recent research has shown that many osteochondromas are inherited autosomal inherited diseases. Gene line mutations in the EXT1 and EXT2 genes located on chromosomes 8 and 11 have been linked to disease causes. Treatment options for osteochondroma are surgical removal of solitary lesions or partial excision of growth, when symptoms cause limitation of motion or nerves and throwing of blood vessels. In Hereditary multiple exostoses the indications of surgery are based on several factors taken collectively ie; patient age, location and number of tumors, accompanying symptoms, aesthetic concerns, family history and underlying gene mutations. Various surgical procedures have been used to correct some hereditary eksostosis such as osteochondroma excision, elongation of bones, corrective osteotomy and hemiepiphysiodesis. Sometimes a combination of previous procedures is used. The surgical success indicators associated with disease and patient characteristics are highly debated. Because much of the research on some retrospective hereditary eksostosis and sample size is limited with missing data, the best evidence for each surgical procedure currently practiced is lacking.
Video Osteochondroma
Mekanisme
Osteochondromas long and slender, stemmed on the stalk often take the form of cauliflower. The cartilage cover is covered by the fibrous perichondrium and continues with the bony periosteum underneath. Cartilage is less than 2 cm and thickness decreases with age. Cover more than 2 cm, indicating a malignant tumor transformation. The cartilage lid fuses with a long bone epiphyseal area called spongiosa. In spongiosa, chondrocytes are arranged according to epiphyseal growth plates. Spongiose from the stalk continues with the underlying cancellous bone. Fractures in the stalk cause fibroblastic proliferation and new bone formation. The development of bursa takes place over the osteochondroma, which is attached to the perichondrium cap. Bone inflammation is indicated by the bursal wall lined with synovium. As a result, the patient may experience years of swelling associated with the location and location of the lesions indicating mechanical obstruction, nerve impulse, pseudoaneurism of the above vessels, fractures in the stem of the lesion, or the formation of bursa over osteochondroma. Sulfate (HS) is a glycosaminoglycan involved in proteoglycan formation. HS biosynthesis takes place in the Golgi apparatus and the endoplasmic reticulum, where the glycosaminoglycan chain is managed by glycosyltransferase type II encoded by the gene EXOSTOSIN Ext1 and EXT2 . A decrease in HS levels causes mutations in EXT1 or EXT2 to cause skeletal abnormalities. The underlying mechanism for solitary osteochondroma and has been associated with multiple genetic changes in genes Ext1 or EXT2 which is located on chromosome 8 and 11. About 65% osteochondroma appeared in > Ext1 gene loci on chromosomes 8 and 35% appears in the gene locus EXT2 on chromosome 11. Approximately 70-75% of multiple osteochondroma is caused by a point mutation, often involving the removal of a single or multiple axons like which is found in 10% of all hereditary cases. About 10-15% of all cases no genome changes are detected. The mechanism behind the formation of some osteochondromes is the massive removal of the genes of the EXT1 and EXT2 genes. The mechanism identified behind solitary osteochondromas is the removal of homozygotes from the EXT1 gene. However, the exact cause of osteochondroma is unknown. In addition, the molecular basis of genetics and the clinical variability of some osteochondromes as well as the underlying cause of malignant and osteochondromal onset transformations in negative patients' negative EXT are also currently unknown.
Maps Osteochondroma
Symptoms
Limited function and normal movement caused by osteochondromas that grow slowly and deeply. The majority of osteochondroma are asymptomatic and found incidentally. Any individual with osteochondroma may experience different symptoms and most of the time the individual will not experience any symptoms at all. Some of the most common symptoms are painless, painless muscles, muscle pain, and pressure or irritation with strenuous exercise. The main symptoms arise when complications such as fractures, bone deformities or mechanical joint problems occur. If the occurrence of osteochondroma near the nerve or blood vessels, affected limbs may experience numbness, weakness, loss of pulse or discoloration. Periodic changes in the bloodstream can also occur. Approximately 20% of patients with nerve compression generally recognize vascular compression, arterial thrombosis, aneurysm, and pseudoaneurism. The formation of pseudoaneurysm and venous thrombosis leads to claudication, pain, acute ischemia, and symptoms of phlebitis. If a tumor is found beneath the tendon, it can cause pain during movement causing restriction of joint movement. Pain can also occur due to bursal inflammation, swelling or fracture at the base of the stem of the tumor. Some of the clinical signs and symptoms of malignant osteochondroma are pain, swelling, and mass enlargement.
Diagnosis
Osteochondromas are often asymptomatic and do not cause any discomfort. They are often discovered accidentally when X-rays are performed for unrelated reasons.
- X-rays are the first tests performed that characterize the lesion. They show a clear picture of solid bone structure, and will also indicate bone growth associated with osteochondroma. Computed Tomography (CT) scanning can identify bone lesions in excellent detail and indicate the presence of calcification. These tests also provide great details, especially in soft tissue with the auxiliary image cross section. Magnetic resonance imaging (MRI) is the most accurate method for detecting bone mass in symptomatic cases to describe the exact morphology of the tumor. It is used to verify whether the mass is palpable continuously with the affected bone cortex and to distinguish osteochondroma from other lesions on the bone surface. MRI can also be used to search for cartilage on tumor surfaces and can describe vascular complications caused by tumors. MRI can identify tumors in the spine and is often used to diagnose low-grade osteosarcoma.
- Ultrasound is performed if aneurysms or pseudoaneurysms and venous or arterial thrombosis are suspected. Ultrasound is an accurate method for checking the cartilaginate stamp of osteochondroma. This is also a way to find bursitis. However, it can not be used to predict whether the growth of the tumor in relation to the cap.
- Angiography is used to detect vascular lesions caused by osteochondroma due to the harsh cartilage cap. It is also used to characterize malignant transformation lesions through neovascularity.
- Clinical trials such as sequence analysis can be performed from all coding areas both EXT1 and EXT2 to detect mutations.
- Biopsy of tumor tissue samples can also be taken to check for cancer.
Tests for osteochondroma can also identify diseases such as secondary peripheral chondrosarcoma and multiple osteochondromatosis. In large, secondary chondrosarcoma appears on the osteochondroma site because the increase in cartilage-cover thickness indicates the potential for malignant transformation. Symptoms of some osteochondromatosis are similar to solitary osteochondroma, but they are often more severe. A painless lump can appear at the site of the tumor and pain and other discomfort can also occur if pressure is placed on soft tissue, nerves, or blood vessels. Dysplasia Epiphysealis Hemimelica (DEH) or Trevor's disease and metachondromatosis (MC) are considered as differential diagnoses for solitary and hereditary osteochondromes. DEH is described as an over growth type in one or more epiphyses. Similar to osteochondroma, DEH is diagnosed before the age of 15 years and the growth of the lesion ends at puberty, when the growth plate closes. Metachondromatosis is a rare disorder that exhibits symptoms of some osteochondromas and enchondromas in children and is also inherited in autosomal dominant mode.
Treatment and prognosis
Osteochondromas are benign lesions and do not affect life expectancy. The complete excision of osteochondroma is curative and recurs when the tumor removal is imperfect. Some reoccurrences in well-excised lesions suggest that it may be malignant. The risk of malignant transformation occurs in 1-5% of individuals. If there are symptoms of a cancerous tumor, then the patient should be evaluated by a bone specialist. No treatment is needed for solitary osteochondroma asymptomatic. Treatment for solitary osteochondroma is a careful observation over time and taking x-rays regularly to monitor any changes in the tumor. If the lesion causes pain with activity, nerve or vascular implosion, or if bone growth is fully mature and a large cartilage protrudes prominently, it is recommended that the tumor be removed surgically.
Osteochondromas have a low malignancy rate (& lt; 1%) and tumor resection is recommended if symptoms such as pain, restriction of movement, or surge in nerves or blood vessels occur. Resection of the tumor also occurs when the tumor increases in size and progresses to malignancy. During surgical resection, all lesions together with cartilaginous cap must be removed to minimize the possibility of re-occurrence. Surgical treatment is the only treatment option if general complications such as fractures, peripheral nerve symptoms such as paresthesia, paraplegia, peroneal neuropathy, and upper extremity neuropathy occur. Prophylactic resection is recommended if the lesion is located next to the blood vessels.
Depending on the size and location of the tumor, the time required to return to normal daily activity varies between individuals. Restrictions on some activities are advised if pain or discomfort continues after surgical excision.
Research
Research done using Zebrafish dackel (dak) has shown that in EXT2 -/- Zebrafish, chondrocytes fail to undergo terminal differentiation and bone formation fails to progress from the pre-osteoblast stage to osteoblast. In contrast, abnormal lipid deposition and premature adipocyte differentiation occur. The expression of xbp1 , the main regulator of
References
External links
Source of the article : Wikipedia
0 Comments