Oncologic outcome of parosteal osteosarcoma

Background This retrospective review evaluated the clinical features and surgical outcomes of parosteal osteosarcoma (POS). Methods Nine patients were surgically treated and followed up. Their mean age was 30.8 years. Clinical information and oncologic outcomes of each case were analyzed. Results Sites of involvement were all in the femur, and all tumors arose from the metaphyseal area of the distal femur. Biopsies for definite diagnoses were performed in just two of the nine cases. Wide resection was applied for all tumors. Surgical evaluations were a 1-cm-wide procedure in six cases and a 2-cm-wide procedure (or more) in three cases. All patients were found to be continuously disease free during the follow-up period of 115.1 months. Conclusion POS showed characteristic findings on radiographic images. Therefore, wide resection without biopsy could be performed in 77.8% (7/9) of the cases. This procedure may contribute to attaining better limb function, because of preventing contamination of healthy surrounding tissue and minimizing the extent of resection. The safety margin was evaluated as a 1-cm-wide procedure. For the choice of reconstruction, indication of autobone grafting (3/9) or total knee replacement (TKR) (6/9) depended on tumor size, location, and shape. With no adjuvant treatments, all cases have shown good clinical courses during the entire follow-up period of about 10 years.