High-Grade Surface Osteosarcoma: Clinical Features and Oncologic Outcome.

Background: High-grade surface osteosarcoma is an extremely rare subtype of osteosarcoma. The treatment outcome for this tumor varies in different centers.

Methods: This was a retrospective study of high-grade surface osteosarcoma; clinical, radiological, and histological materials were reviewed.

Results: We studied 23 patients (16 males, seven females); median age was 24 years old. All the tumors involved the lower limb, located at the diaphysis in 11 patients and at the metaphysis in 12 patients. Even though the majority of tumors were located at the surface of the bone, the medullary canal was involved in 10 patients. The microscopic findings were indistinguishable from conventional central osteosarcoma. All the patients were treated with a combination of surgery and systemic chemotherapy. Follow-up data were completed in 20 patients; follow-up duration ranged from 27 months to 182 months or until the patient died of the disease (5-104 months). Of the 20 patients, 12 died of the disease, and eight patients were alive at the time of the last follow-up. The 5-year overall survival rate was 37.6%.

Conclusions: Our study revealed that the treatment outcome for this tumor shows a poor survival rate.