ABSTRACT
Acanthosis implies hyperplasia or increased thickening of the stratum Malpighii. Usually the rete ridges are preserved, elongated and/or thickened. The suprapapillary portions of the epidermis may appear thinned (psoriasis), normal or thickened. Acan thosis is subdivided into regular, when the rete ridges end at about the same level, and irregular. We used the term lacelike acanthosis when there is elongation of rete ridges without thickening of epidermis.
