What are the common diseases that result from excessive proliferation?

Abnormally excessive cell proliferation is the cause of many different types of cancers. Malignancies can result from excessive proliferation of any type of cells in the body. The harmful effects on the body are mainly caused by the increase in the quantity of tumor cells. Breast, lung, colon, and prostate cancers are all caused by excessive proliferation of cells in their respective organs. If the cancer cells divide at a faster rate, it indicates that the cancer is spreading faster or becoming more aggressive. Leukemia and lymphoma are blood cancers which originate from the lymphocytes. Leukemia originates in the bone marrow and spreads via the bloodstream, and lymphoma originates in lymph nodes or the spleen and spreads through the lymphatic system. In addition to cancers, excessive cell proliferation may lead to other diseases such as atherosclerosis, psoriasis, cirrhosis of the liver, rheumatoid arthritis, and scleroderma. In atherosclerosis, the proliferation and movement of vascular smooth muscle cells are crucial factors in the development of the disease. Psoriasis occurs from the excessive proliferation and atypical differentiation of keratinocytes. In cirrhosis of the liver, hepatic stellate cells play a significant role in the initiation and progression of liver fibrosis. The excessive proliferation leads to the formation of fibrous scar tissue. In rheumatoid arthritis, there is atypical cell proliferation in the synovium (lining of the joints). The synovium becomes flooded with T-helper cells, B cells, and macrophages. This consequently increases the synovial fluid volume, causing inflammation, joint swelling, and pain associated with the disease. Scleroderma is caused by an excessive amount of collagen in body tissues. Atypical immune or inflammatory processes in the body induces cell changes which cause the formation of excess collagen.