Sarcomas (other than Ewing's) of flat bones in children and adolescents. A clinicopathologic study.

The clinicopathologic features and response to therapy of 28 patients with non-Ewing's flat bone sarcoma treated at St. Jude Children's Research Hospital, Memphis, Tennessee, over a 25-year period were reviewed. Twenty-two patients had osteosarcoma, four malignant fibrous histiocytoma, one chondrosarcoma, and one fibrosarcoma. Ages at diagnosis ranged from 3 to 24 years (median, 15 years). Primary sites were craniofacial bones in ten patients, pelvis eight, scapula four, ribs two, metatarsal bones two, clavicle one, and vertebra one. All primary tumors were associated with soft tissue extension; none of the patients had metastatic disease at presentation. Six cases represented second malignancies that arose 5 to 16 years after irradiation for an unrelated tumor. Complete excision was possible in ten patients, eight of whom received postoperative chemotherapy. Five of these patients remain free of disease 1.8+ to 13+ years (median, 8.1 years) from diagnosis. Prolonged remissions after adjuvant chemotherapy were achieved in only two of 18 patients after incomplete surgical resection or biopsy. The median survival time in this group was 1 year (range, 0.2-7.7+ years). The remaining 16 patients had progressive local disease, but only two developed concurrent metastases. Thus, complete surgical resection appears to maximize disease-free survival in patients with non-Ewing's flat bone sarcoma. For the large percentage of patients in whom total resection is not possible, because of soft tissue extension and local invasion of bulky tumors, preoperative chemotherapy may increase the likelihood of complete excision and improve long-term survival.