Imaging Features and Review Literature of Aneurysmal Bone Cyst

Aneurysmal bone cyst (ABC) accounts for 1.4% of all bone tumors and 15% all primary spinal tumors. Radiography shows an eccentric ballooned or aneurysmal, expanded radiolucency, mostly in the metaphysis of long bone. The margin of ABC is usually well circumscribed with or without a sclerotic rim. Trabeculation is sometimes seen in the lesion but without significant mineralization or calcification. In spine, it demonstrates a purely lytic lesion in the posterior elements and body. Six patients in our hospital with primary ABC with histopathologic confirmation were studied with conventional radiographs, contrast-enhanced computed tomography study, contrast-enhanced MRI study and nuclear medicine bone scintigraphy separately. All cases showed expansile radiolucent lesions with soup bubble appearance and one case with pathologic fracture. Relevant literature was also reviewed. We discuss and emphasize characteristic imaging features and clinical course of ABC.