Reversible loss of polarity with abnormality in size and shape of cells is known as :

Dysplasia refers to disordered cellular development often accompanied by metaplasia and hyperplasia. The characteristic changes associated with dysplasia are: Increased number of layers of epithelial cells Disordered arrangements of cells from basal layer to surface layer Loss of basal polarity Cellular and nuclear polymorphism Increased nucleocytoplasmic ratio Nuclear hyperchromatism Increased mitotic activity Metaplasia: It is defined as a reversible change of one type of epithelial or mesenchymal adult cell to another type of adult epithelial or mesenchymal cell usually in response to abnormal stimuli, and often reves back to normal on removal of stimulus. Hyperplasia refers to an increase in the number of parenchymal cells resulting in enlargement of the organ or tissue. Ref: Essential Pathology for Dental Students By Harsh Mohan page 231