Extraskeletal Osteosarcoma: A Case Report

Abstract

Extraskeletal osteosarcoma (ESOS) is a rare malignancy that accounts for about 1 % of all soft tissue sarcomas. In contrast to osteosarcoma of bone which occurs most frequently in children and adolescents, ESOS primarily affects adults in their fourth and fifth decades. The thigh and buttocks are the most common primary tumor sites. There is a slight male to female predominance observed in most series. Generally, wide resection followed by radiotherapy and/or chemotherapy is recommended. Local recurrence usually occurs in more than half of the patients, but distant metastasis, most common to the lung (＞80% of cases), is more common than local recurrence. The mortality rate ranges from 55.4% to 81 % and the median 5 years survival rate is less than 25%. Here we represent a case of ESOS, which had been recurred many times after primary resection. We gave a high adjuvant radiation dose (7020 cGy) using the conedown fields technique and 6 cycles of epirubicin after wide excision of the recurrent tumor. Treatment related toxicities were limited to the treatment course and this student was able to continue his schooling while undergoing treatment. To date, no particular method of treatment seems to alter the survival rate of ESOS. After a short period of follow up, however, the combined modalities therapy, in our experience, has attained the object of initial local and systemic disease control.