Acanthosis means

HISTOPATHOLOGIC TERMS Before describing the pathology of common skin diseases, the following pathologic terms in common use need to be defined for the understanding of Dermatopathology: Acanthosis: Thickening of the epidermis due to hyperplasia of stratum Malpighi. Acantholysis: Loss of cohesion between epidermal cells with formation of intraepidermal space containing edema fluid and detached epithelial cells. Dyskeratosis: Abnormal development of epidermal cells resulting in rounded cells devoid of their prickles and having pyknotic nuclei. Dyskeratosis is a feature of premalignant and malignant lesions and is rarely seen in benign conditions. Hyperkeratosis: Thickening of the horny layer. Parakeratosis: Abnormal keratinization of the cells so that the horny layer contains nucleated keratinocytes rather than the normal non-nucleate keratin layer. Spongiosis: Intercellular edema of the epidermis which may progress to vesicle formation in the epidermis. Pigment incontinence: Loss of melanin pigment from damaged basal cell layer so that the pigment accumulates in the melanophages in the dermis. Ref: Textbook of pathology (Harsh Mohan)6th edition, page no.769