Cartilage as the cricoid cartilage and carina. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of collagenous extracellular matrix, abundant ground substance that is rich in proteoglycan and elastin fibers. Cartilage is classified in three types, "elastic cartilage", "hyaline cartilage" and "fibrocartilage", which differ in relative amounts of collagen and proteoglycan. Cartilage does not contain blood vessels (it is avascular) or nerves (it is aneural). Nutrition is supplied to the chondrocytes by diffusion. The compression of the articular cartilage or flexion of the elastic cartilage generates fluid flow, which assists diffusion of nutrients to the chondrocytes.
Chondrosarcoma themselves, both of which are directly linked to the propensity of the cancer to invade locally, and to spread widely to distant organs and sites in the body (called metastasis). Grade 1 chondrosarcoma grows relatively slowly, has cells whose histological appearance is quite similar to cells of normal cartilage, and have much less aggressive invasive and metastatic properties. Grades 2 and 3 are increasingly faster-growing cancers, with more varied and abnormal-looking cells, and are much more likely to infiltrate surrounding tissues, lymph nodes, and organs. Some, but not all, authorities and medical facilities assign a "Grade 4" to the most