More than 100 types of cancer develop in the various organs in the body. Cancers are described according to where in the body the cancer originated, what type of tissue it originated in, and what type of cell it started in. For example, breast cancer describes any cancer that originated in the breast. If the cancer spreads to a new organ, such as the lungs, the tumor is called metastatic breast cancer, not lung cancer.
Connective Cell TissuesConnective tissues include bone, cartilage, fat, ligaments, and tendons. These tissues support and connect parts of the body. The structure varies depending on the purpose of the tissue. The diagonal red band in this image shows elastin fiber, which allows connective tissue to spring back into shape following deformation. Cancers called sarcomas orginate in connective tissues. Rare, sarcomas constitute only about 2 percent of all human cancers. Sarcomas are elusive in their early stages. They may arise deep within connective tissues, making them more likely to spread to distant parts of the body before they are detected.
Cancers are further identified according to the type of cell affected. For example, squamous cells are flat, scalelike cells found in epithelial tissue. Cancers that originate in these cells are called squamous cell carcinomas. Adenomatous cells are glandular or ductal cells, and carcinomas that originate in these cells are called adenocarcinomas. Sarcomas that develop in fat cells are called liposarcomas, and those that develop in bone cells are called osteosarcomas.
