Extraskeletal osteosarcoma of the hand: a case report and literature review of the pathophysiology and treatment

Extraskeletal osteosarcoma (ESOS) is a very rare form of primary osteosarcoma that is histologically characterized by tumorous osteoid production with no association with bone. ESOS accounts for less than 5% of all osteosarcoma and 1% of all soft-tissue tumor. The prevalence of ESOS in the upper limbs is approximately 20% and only five cases of ESOS of the hand have been reported. To achieve curative surgical margin for hand sarcomas, amputation is essential for certain cases, and ESOS is not exceptional. Although adjuvant chemotherapy and radiotherapy remain controversial in the treatment of ESOS, because of the hand's functional importance, adjuvant therapies with surgery should be considered. We report a case of ESOS of the hand treated successfully with marginal resection and subsequent adjuvant chemotherapy and radiotherapy. The function of the affected hand was satisfactorily preserved and no evidence of relapse occurred for 46 months from the initial diagnosis. In this case report, we reviewed the previous reports of ESOS, namely, five cases of ESOS of the hand, and even though the role of adjuvant chemo- and/or radiotherapy remains controversial, we propose that marginal resection with adjuvant chemo- and radio-therapy are recommended for ESOS of the hand to achieve satisfactory oncological and functional outcome.