EPIDERMAL HYPERPLASIA (G. huper "over, above G plasso "to mold " G. -ia "forming")

An increased number of cells, especially spinous ones, in a thickened epidermis. We employ it as a synonym for acanthosis because the latter is a parochial term restricted in scope to cutaneous pathology. Because dermatopathology and general pathology are one pathology, one language should be used for both. Strictly speaking, "epidermal hyperplasia" applies also to an increased number of cells in the cor'nified layer, but, by convention, that abnornrality is termed hyperkeratosis. So, too, epidernral hyperplasia includes an increased number of granular cells, but, by custom, that phenomenon is designated hypergranulosis. For the aforementioned reasons, we use epidermal hyperplasia as a synonym for spinous cell hyperplasia of the viable epidermis.