The extremity of a long bone where it joins the epiphysis (see BONE – Growth of bones).
n. the growing portion of a long bone that lies between the *epiphyses (the ends) and the *diaphysis (the shaft).
(osteogenic sarcoma) n. a highly malignant tumour arising from within a bone, usually in the *metaphysis of the long bones of the body and especially around the knee and the proximal end of the humerus. It is usually seen in children and adolescents but can occur in adults of all ages, occasionally in association with *Paget’s disease of bone. In children the usual site for the tumour is the leg, particularly the femur. Secondary growths (metastases) are common, most frequently in the lungs (though other sites, such as the liver, may also be involved). The symptoms are usually pain and swelling at the site of the tumour and there is often a history of preceding trauma, although it is doubtful whether this contributes to the cause. Treatment of disease localized to the primary site was traditionally by amputation of the limb; limb-sparing surgery is now possible after *neoadjuvant chemotherapy, with replacement of the diseased bone by a metal prosthesis. Many centres also give *adjuvant therapy in an attempt to kill any microscopic tumour that might have already spread. The drugs used include doxorubicin, cisplatin, vincristine, cyclophosphamide, and methotrexate.... osteosarcoma
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