features of bone sarcomas at mahak children hospital, tehran, iran during 2007-2009

background: bone sarcomas are the most common malignancies of bone tissues in children, and are classified intotwo groups as osteosarcoma and ewing’s sarcoma. treatment and prognosis depend on the subtype and grade ofthe tumor. the goal of this study was to evaluate the features bone sarcoma in patients referred to mahak childrenhospital since 2007 to 2009.materials and methods: this was a retrospective study of patients with bone sarcoma referred to mahakchildren hospital for continuing their treatment or as a new case of cancer. all of the patients had local pain, localswelling, and decreased range of motion and pathologic fractures as the presenting symptom. all patients underwentbone scan, chest computed tomography (ct) scan, chest x- ray, echocardiography, hearing tests, and bonemarrow aspiration/biopsy. all of the data were analyzed by sas software.results: in this study, 36 patients with bone sarcoma were included with the age range of 3 to 20 years old (55% maleand 45% female). analysis showed that local pain and local swelling were the most frequent local manifestations inpatients. the most common primary tumor site was distal femur (30%). treatment for the patients at mahakchildren hospital is performed according to german protocol. out of 36 patients, 75% were followed until 2008 and25% until 2009.conclusion: according to the analysis we can conclude that these data are similar to other studies. to achieve thebest results, oncologists have to modify the treatment of patients completely.