Hyperplasia (from ancient Greek ὑπέρ huper, "over" + πλάσις plasis, "formation"), or hypergenesis, is an increase in the amount of organic tissue that results from cell proliferation. It may lead to the gross enlargement of an organ, and the term is sometimes confused with benign neoplasia or benign tumor.Hyperplasia is a common preneoplastic response to stimulus. [Source: Wikipedia ]