A. Brief Descriptions：
20% of primary bone cancers.
Usually arise in the metaphyseal region of the long bones of the extremities.
Radiographically it reveals Codman’s triangle and bony spiculus (sun ray appearance).
B. Gross Findings：
Gritty or gray-white.
Contain areas of hemorrhage and cystic degeneration.
C. Micro Findings：
The tumor cells vary in size and shape and frequently have large hyperchromatic nuclei.
Wovening bone formation.
Bizarre tumor giant cells are common, as are mitoses.
Robbins Pathologic Basis of Disease, 6th ed. P1236-1237.
【 Fig. 158-1 (LP)】 A network of thin and broader trabeculae of osteoid.
【 Fig. 158-2 (LP)】
【 Fig. 158-3 (HP)】The tumor cells vary in size and shape and frequently have large hyperchromatic nuclei.