Blue whitish veil
Blue-white veil is confluent blue pigmentation with an overlying white “ground-glass” haze. In melanoma, the bluewhite veil does not occupy the entire surface area of the lesion, but rather is present as a focal, ill-defined area. Histopathologically, this dermoscopic structure corresponds to an aggregation of heavily pigmented cells (melanocytes and/or melanophages) or melanin in the dermis (blue color) in combination with compact orthokeratosis  . At times, it is difficult to distinguish between regression structures (namely melanosis) and blue-white veil by dermoscopy because both structures display blue-white color. However, examining the lesion without dermoscopy can help differentiate between blue-white color due to regression versus due to deep melanocytes. In regression the surface contour will be flat (macular) and in blue-white veil the surface will be raised and palpable. In melanoma the blue-white veil is nonuniform in color and is present focally within the lesion. In contrast, the blue-white veil has a uniform steel-blue color in blue nevi and it occupies the entire surface area of the lesion.