Chondrosarcoma Health Article

Definition

Chondrosarcoma is a malignant tumor that produces a special type of connective tissue called cartilage. Malignant tumors have cells that have the ability to invade and are characterized by uncontrolled growth.

Description

Cartilage is a type of connective tissue that acts as a resistant surface. Cells called chondrocytes produce cartilage. Chondrosarcoma is a malignant growth arising in chondrocytes. There are two types of chondrosarcomas, either primary or secondary. Primary chondrosarcomas arise in areas of previously normal bone that are derived from cartilage. Secondary chondrosarcomas are lesions produced from pre-existing cartilage lesions. The chondrosarcoma tumors either produce enlargement or erosion of the area involved. The lesion is classified further as to where the lesion occurs and the grade of the lesion. It is graded from 1 (low-grade) to 3 (high-grade). This classification states that the higher the grade of the tumor, the higher the increased atypia, or abnormal cell growth.

Two non-cancerous diseases, Maffuci disease and Ollier disease, are similar to chondrosarcoma. Ollier disease, also known as enchondromatosis or dyschondroplasia, is a disorder affecting the growth plates of bone where new bone is deposited. The cartilage laid down is not reabsorbed and masses form near the ends of the long bones such as the thigh bone (femur) and upper arm bone (humerus). Maffucci disease has the same abnormalities as Ollier disease as well as soft tissue destruction including the skin. Patients with Maffucci or Ollier disease should have bone scans every three to five years to monitor potential malignant transformations.

Genetic profile

Anomalies of chromosomes 5, 7, 8, and 18 and structural alterations of chromosomes 1, 12, and 15 are commonly found in patients diagnosed with chondrosarcoma. Interestingly, the gene for the area of normal cartilage production, type II collagen, has been found in the same regions as chondrosarcoma. Studies on the tumor suppressor gene, EXT1, have shown that changes (mutations) of this gene may also be important in the growth of chondrosarcoma.