Moles Intradermal Nevi
Intradermal nevi are seen mainly after adolescence. Intradermal nevi are elevated, fleshy, and slightly or moderately pigmented papules. Lesions vary in size from a few millimeters to a centimeter. Dermal nevi are brown or black, but may become lighter or flesh-colored with time. Pigmentation may be arranged in flecks. Course, dark, terminal hairs may grow from the nevus. The variety of shapes reflects the evolutionary process in which moles extend downward with age and nevus cells degenerate or become replaced by fat and fibrous tissue.
Dome-shaped lesions are the most common. They generally appear on the face and are symmetric, with a smooth surface. They may be white or translucent, with telangiectatic vessels on the surface mimicking basal cell carcinoma. The structure may be warty or polypoid. Pedunculated lesions with a narrow stalk are located on the trunk, neck, axilla, and groin. They may appear as a soft, flabby, wrinkled sack. Elevated nevi are exposed and are prone to trauma from clothing and other stimuli, often causing them to bleed and inflame, influencing some patients to suspect malignancy. White borders may appear, creating a halo nevus. Degeneration into melanoma is very rare, but dermal nevi may resemble nodular melanoma; therefore, knowledge of duration is important. Nests and cords of nevus cells are found within the dermis; they may extend into the subcutaneous fat. Melanocytic cells are pale, uniform in size and are found in cords or clusters surrounded by collagen bundles in the dermis.