Retroperitoneal extraskeletal osteosarcoma: imaging findings and transarterial chemoembolization.

Extraskeletal osteosarcoma (EOS) is an uncommon and usually highly aggressive mesenchymal tumor. Retroperitoneal extraskeletal osteosarma (REOS) is exceedingly rare. Due to the rare nature of the disease, both the diagnosis and the management of REOS can be challenging. We present the clinical history, CT findings, angiographic manifestations, and use of transarterial chemoembolization for treatment in a case of REOS. To our knowledge, the angiographic features of and attempt at transarterial treatment of REOS have not been reported in the literature.