Osteosarcoma in Paget's Disease of Bone

This image is from the same case as the two previous images. Pagetoid bone can be seen to the left consisting of irregularly thickened trabeculae with blue cement lines. In the right half of the image, the thickened bony trabeculae are replaced by delicate lace-like osteoid, numerous giant cells, and a spindle cell proliferation. The histologic features are those of fibroblastic osteosarcoma complicating Paget's disease of bone.