Figure 1.

(a) Permeative lytic lesion in the proximal femur diaphysis (arrows) on the lateral left hip radiograph of a patient presenting with left hip pain. There is also a suggestion of irregular periosteal reaction (arrowhead). (b) Dedicated femur radiograph better shows a laminated peristeal reaction (arrowheads) but the permeative lytic lesion is more subtle (arrow). (c) Bone scan with technetium-99m methylene diphosphonate shows intense tracer uptake at the corresponding area. (d) Contrast-enhanced T1-weighted fat-saturated MR image showing marrow enhancement in the femur (arrow) and surrounding enhancing extra-osseous soft tissue mass (black asterisk). Biopsy subsequently confirmed a diagnosis of PBL.