Fig. 2

Preoperative computed tomography (CT) (sacrum). Non-enhanced CT scan (a transversal soft tissue window; b transversal bone window; d sagittal soft tissue window; e sagittal bone window): osteolytic lesions surrounded by cystic low-density soft-tissue masses of unequal-size, largest in anterior-right (red arrows). Contrast-enhanced CT (c transversal; f sagittal): soft-tissue masses with heterogeneous ring enhancement and unremarkable central enhancement (red arrows)