2Most of them are highly malignant and affect children frequently. Regional lymph nodes are rarely affected.Bone neoplasms change or destroy the structure of the bone, and accordingly they show up as characteristic lesions in the radiographs.As clinical features such as pain, swelling and discomfort are nonspecific, a long period of timemay elapse until the correct diagnosis is achieved.
5Osteoid Osteoma…uniquely painful benign lesions that most commonly occur during adolescence.Males are af ected more commonly than females.Most lesions occur in the meta- or diaphysis of the long bones (proximal femur and tibia) although, as with osteoblastoma, spinal lesions can lead to painful scoliosis.
11Osteoblastoma Osteoblastoma is a rare benign bone tumor. Patients often complain of intermittent episodes of pain. The clinical course is usually slow and indolent, but osteoblastomas can progress rapidly, mimicking a malignant process.The usual age of onset is adolescence to early adulthood, but the clinical presentation is variable.Males are affected more commonly than females.
12CLINICAL SYMPTOMS Muscle atrophy or muscle spasm. Spinal osteoblastomas occur in the posterior elements; muscle spasm in this area can lead to a painful scoliosis.
13X-RAYAP radiograph of the distal femur shows a purely lytic osteoblastoma in the epiphysis and metaphysis with mild osseous expansion but no evidence of sclerosis or mineral production
14AP radiograph of the pelvis shows a densely sclerotic osteoblastoma in the left sacrum. Due to the extent of sclerosis, this lesion was initially mistaken for an osteosarcoma
17EnchondromaEnchondromas are relatively common benign intramedullary cartilaginous lesions that often are detected incidentally.The peak age is the second decade. Half of enchondromas occur in the short tubular bones of the hands and feet followed by proximal humerus and proximal and distal femur.Some enchondromas are painful and appear more aggressive radiographically but still display the bland, benign histology typical of asymptomatic lesions
18Periosteal ChondromaPeriosteal chondromas are benign intracortical cartilaginous lesions.Most patients are asymptomatic.Lesions that become especially large may cause local mechanicalsymptoms or bursitis.Depending on the size of the lesionand the patient’s body habitus, lesions may be palpatedon physical examination.The majority of the patientspresent within the second through the fourth decades of life
19Periosteal chondroma of the proximal humerus. The lesion is arising in the cortex of the proximal humeral metadiaphysis laterally. These lesions frequently result in a concave, scalloped deformity of the cortex with a sclerotic rim along the medullary side. Some lesions have an identii able shell of bone along the soft tissue margin. They may or may not have identii able calcii ed matrix mineralization
21OsteochondromaOsteochondromas are benign cartilage capped bony projections arising from the external surface of the bone that are ot en asymptomatic.h ey may become painful due to compression of overlying structures or due to overlying bursa formation.Sudden pain may be due to a fracture through the stalk. Most patients present in the i rst three decades.Patients with multiple osteochondromatosis or with lesions close to physes frequently have developmental deformity.h ere is a small (less than 1%) risk of transformation to a low-grade chondrosarcoma.Lesions that continue to grow at er skeletal maturity and that havecartilage caps greater than 1–2 cm should be examined carefully for malignant degeneration.
35Ewing’s Sarcoma/Primitive Neuroectodermal Tumor (PNET) Most patients present with local or regional pain from he lesion.Swelling and a palpable mass may develop subsequently.Most patients will have pain at rest or at night; signii cant mechanical or activity-related pain may herald pathologic fracture.Many patients develop signs and symptoms of infection.Lesions are ot en permeative with a broad zone of transition between the lesion and the surrounding bones.Lesions typically present in the diaphysis or metadiayphisis of long bones, although l at bones such as the pelvis and scapula may also be involved.
39Differential diagnosis of tumours Non-malignant tumoursMalignant tumoursPains absent or insignificantPain is intensive, especially nightlyGrow slowlyGrow quicklySometimes arrive at very largenessesLarge size arrive at rarelyHaven’t metastasesEarly give metastasesHave opposition growth, wedge off surrounding fabrics, often limited a capsuleHave infiltration growth, a border with surrounding fabrics is not clearPrognosis favourablePrognosis doubtful