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 disordered proliferation of mature tissues that is native to the site of origin, e.g., exostoses, nevi and soft tissue hamartomas. Although most hamartomas are benign, some histologic subtypes, e.g., neuromuscular hamartoma, may proliferate aggressively such as mesenchymal cystic hamartoma, Sclerosing epithelial hamartoma, Sclerosing metanephric hamartoma.