FIG. 2
Osteosarcoma. (Low power.)
PLATE XX
Melanosarcoma of Skin. (Dry high power.)
The microscopic picture of these tumors varies greatly, the endothelial cells often shaping and grouping themselves so as to imitate epithelioma. In doubtful cases the primary location or origin of the growth should be ascertained.
Endotheliomas are mainly of rapid growth, and often show a high degree of malignancy. If thoroughly extirpated before metastasis has occurred, prognosis is fair; but metastases happen early because of the direct connection of the tumor with the lymph current.
Fig. 80
