Malignant Transformation of an Aneurysmal Bone Cyst to Huge Fibroblastic Osteosarcoma without Radiation Exposure: Proper Surgical Management is More than a Challenge

Abstract

In this study, we present a case of aneurysmal bone cyst presenting as pathologic fracture of the left proximal femur. The patient, who had history of multiple surgeries, was referred to us with a giant mass. The patient was found to develop osteosarcoma without radiation exposure. External hemipelvectomy was performed.Appropriate surgical management of a huge tumor that repeatedly operated is more than a challenge like this case. Aneurysmal bone cysts rarely present as pathologic fractures initially. In addition, to the best of our knowledge, the number of aneurysmal bone cysts (ABCs) exhibiting malignant transformation to osteosarcoma without radiation exposure is less than ten in the literature.Keywords: aneurysmal bone cyst, osteosarcoma, malignant transformation, hemipelvectomy