Osteosarcoma - ț̢
A sarcoma originating in bone-forming cells, affecting the ends of long bones. It is the most common and most malignant of sarcomas of the bones, and occurs chiefly among 10- to 25-year-old youths. (From Stedman, 25th ed)
Osteosarcoma, Juxtacortical - ț̢
A form of osteogenic sarcoma of relatively low malignancy, probably arising from the periosteum and initially involving cortical bone and adjacent connective tissue. It occurs in middle-aged as well as young adults and most commonly affects the lower part of the femoral shaft. (Stedman, 25th ed)