Sarcoma of femur following fracture—i. e., developing in callus. (Original.)
Giant or multinuclear cells should be present in considerable numbers to entitle a tumor to classification in this group. When round cells, spindle cells, or giant cells mingle in nearly equal proportion the tumor should be called a mixed-cell sarcoma.
D. Osteosarcoma.
—Osteosarcoma is something more than sarcoma of bone, which latter may spring from the fibrous or medullary elements. It is sarcoma of the specific bone-forming connective tissue, including the osteoblasts and osteoclasts; in other words, of the stroma of the bone. Under these circumstances real bone develops throughout the tumor, and it is essentially a bony neoplasm. In like manner there may be true osteofibroma. These tumors are to be distinguished, even clinically, from the medullary sarcomas, which develop within the bone and expand it, even to enormous proportions, the bony covering then being a mere shell.
E. Chondrosarcoma.
—Chondrosarcoma resembles osteosarcoma in that it is sarcoma of the stroma of cartilage, or of the specific tissue which produces cartilage. In it true cartilage (white fibrous) also is found throughout the tumor. Chondrofibroma is also possible. (See [Plate XIX].)
F. Endothelioma.
—Endothelioma has been called various names, and its true character has been only lately determined. It is composed particularly of the endothelial cells which line the lymph spaces, and which have no peculiar secretion. It is met with most often in the skin (especially of the face), in the parotid region, in the genital glands, the bones, the lymph nodes, and dura.
PLATE XVIII