Each and every living cell in the human body that is capable of cell division has the potential to become cancerous (malignant). Since there are many types of cells in the body, there could be as many types of cancers. About 200 cancers are already known to affect human beings. A generic name is usually given to a group of cancers, depending on the type of the cells of their origin such as carcinoma, sarcoma, myeloma, leukaemia and lymphoma.
Carcinoma: Cancers arising from the epithelial cells are called carcinomas. This is the single largest group of cancers comprising about 80 per cent of all the human cancers. Carcinomas are further divided into squamous cell carcinomas, basal cell carcinomas and glandular cell carcinomas (adenocarcinomas).
Sarcoma: Cancers arising from the connective tissue (mesenchymal) cells are called sarcomas. The sarcomas include cancers arising from the bone, cartilage, muscle, fatty tissue and fibrous tissue.
Myeloma: Cancers arising from the plasma cells are called myelomas.
Leukaemia: Cancers arising from the blood-forming cells are called leukaemias.
Lymphoma: Cancers arising from the cells of lymphatic tissue are called lymphomas
Similarly, malignant tumours of the central nervous system are named according to the type of cells of their origin; for example, cancer arising from the glial cells is called glioma.