Chondrosarcoma is a malignant bone tumor arising from cartilaginous tissue, most frequently occuring at the ends of the femur and tibia, the proximal end of the humerus and the pelvis; and presenting with a palpable mass and progressive pain. Chondrosarcoma is usually slow growing at low histological grades and can be well managed by intralesional curettage or en-block wide resection.

A neoplasm arising in the neuroectoderm, the portion of the ectoderm of the early embryo that gives rise to the central and peripheral nervous systems, including some glial cells.