Figure 11e. Conventional intramedullary chondrosarcoma of the acetabulum in a 52-year-old woman with a 2-year history of right hip and leg pain. (a) Anteroposterior hip radiograph shows subtle sclerosis caused by chondroid matrix mineralization and bone destruction of the ilium and iliopectoneal line cortex lesion center at the previous site of the triradiate cartilage (arrows). (b) Axial CT scan reveals an extensive low-attenuation soft-tissue mass (M) about the hip and faint intraosseous matrix mineralization (arrow). (c) Axial gadolinium-enhanced T1-weighted (666/10) MR image with fat saturation demonstrates peripheral and septal enhancement of both the soft-tissue and intraosseous components of the tumor (arrows) with hip joint invasion (arrowhead). (d) Coronal T2-weighted (3,300/102) MR image demonstrates soft-tissue extension (M) and high signal intensity similar to that of the bladder (B). (e) Photograph of the sagittally sectioned gross specimen demonstrates extensive marrow involvement (C), the soft-tissue mass (M), and joint invasion inferiorly (arrow).