Cancer

There are several different types of cancers:

• Carcinomas are cancers that arise in the epithelium (the layers of cells covering the body's surface and lining the internal organs and various glands). Ninety percent of human cancers fall into this category. Carcinomas can be subdivided into two subtypes: adenocarcinomas and squamous cell carcinomas. Adenocarcinomas are cancers that develop in an organ or a gland, while squamous cell carcinomas refer to cancers that originate in the skin.
• Melanomas also originate in the skin, usually in the pigment cells (melanocytes).
• Sarcomas are cancers of the supporting tissues of the body, such as bone, muscle and blood vessels.
• Cancers of the blood and lymph glands are called leukemia and lymphomas respectively.
• Gliomas are cancers of the nerve tissue.