Paraneoplastic syndromes can also involve the nervous, hematological, renal, gynecologic and gastrointestinal systems. Staging Staging is the process of describing the extent of disease at the time of diagnosis in order assess prognosis and to aid in treatment planning, and compare different treatment approaches. The TNM classification proposed by the American Joint Commission on Cancer is the most frequently use system for defining the extent of disease. An example is given for breast cancer. The three major classifications of normal body tissue are epithelial, connective and muscle, and nerve tissue.
Epithelial tissues cover all external body surfaces and line all internal spaces and cavities.
The skin, mucous membranes, gastrointestinal tract, and the lining of the bladder are examples of epithelial tissues. The functions of epithelial tissues are to protect, excrete, and absorb. Cancer originating in the epithelial tissue is called a carcinoma. Connective tissue consists of elastic, fibrous, and collagenous tissues, such as bone, cartilage, and fat. The function of such tissue is to connect, support, and protect.