Periosteal osteosarcoma: long-term outcome and risk of late recurrence.

The long-term outcome of periosteal osteosarcoma is not well defined. We sought to examine the disease-specific survival and risk of late recurrence or dedifferentiation in a cohort of 29 patients with average of 15.8 years followup. Disease-free survival was 83%, with five patients dying of disease at an average of 26 months after presentation. Survival was similar with respect to anatomic location, pathologic grade, and limb-salvage resection. All instances of local recurrence, metastatic disease, and death occurred within 3 years after presentation. There were no instances of dedifferentiation. Long-term disease-free survival is possible after resection of the local recurrence. Limb-salvage therapy seems to offer survival equivalent to amputation, and there does not seem to be a substantial risk of late recurrence, dedifferentiation, or disease progression.