hyperplasia

     

Hyperplasia (or "hypergenesis") is a general term referring to the proliferation of cells within an organ or tissue beyon that which is ordinarily seen in e.g. constantly dividing cells. Hyperplasia may result in the gross enlargement of an organ, the formation of a benign tumor, or may be visible only under a microscope. Hyperplasia is considered to be a physiological response to a specific stimulus, and the cells of a hyperplastic growth remain subject to normal regulatory control mechanisms. This stands in contrast to neoplasia (the process underlying cancer and some benign tumors), in which genetically abnormal cells proliferate in a non-physiological manner which is unresponsive to normal stimuli.