Syncitial osteoclastic giant cells are seen in all except

Osteosarcoma refer Robbins page no 1216 8th edition Osteosarcomas are bulky tumors that are gritty, gray-white, and often contain areas of hemorrhage and cystic degeneration (Fig. 26-24). The tumors frequently destroy the surrounding coices and produce soft tissue masses. They spread exten- sively in the medullary canal, infiltrating and replacing hemato- poietic marrow. Infrequently, they penetrate the epiphyseal plate or enter the joint. When joint invasion occurs, the tumor grows into it along tendoligamentous structures or through the attachment site of the joint capsule. The tumor cells vary in size and shape and frequently have large hyperchromatic nuclei. Bizarre tumor giant cells are common, as are mitoses, some of them abnormal (e.g. tripolar). Vascular invasion is usually conspicuous, and some tumors also exhibit extensive necrosis. The formation of bone by the tumor cells is diagnostic