dermatologic disorders
Moles
Introduction
Moles are flesh- to brown-colored macules, papules, or nodules composed of nests of melanocytes or nevus cells. Their main significance (other than cosmetic) is their resemblance to melanoma. Pigmented lesions are assessed for characteristics of concern (new or changing appearance, irregular borders, multiple colors within one lesion, bleeding, ulceration, or itching) that could suggest atypical nevi or Melanoma . Almost everyone has a few moles, which usually appear in childhood or adolescence. There are different types of moles (see table). During adolescence, more moles often appear, and existing ones may enlarge or darken. Nevus cells may be eventually replaced with fat or fibrous tissue. Moles typically change consistency, becoming softer and boggy, or firmer, and less pigmented over the decades. Moles may darken during pregnancy. An individual mole is unlikely to become malignant (lifetime risk is approximately 1 in 3,000 for men and to 10,000 for women) ( General reference ); however, patients with large numbers of benign moles ( Blue nevi are benign moles that appear as bluish gray macules or thin papules. The depth and density of pigment in the skin account for the apparent blue color. Moles are flesh- to brown-colored macules, papules, or nodules composed of nests of melanocytes or nevus cells. Moles develop on nearly everybody, and are significant primarily because they can become dysplastic or malignant and need to be differentiated from melanoma. Image provided by Thomas Habif, MD. Junctional nevi are well-demarcated evenly pigmented brown macules and patches. Image courtesy of Marie Schreiner, PA-C. A compound nevus is a well-demarcated brown papule. Image courtesy of Marie Schreiner, PA-C. Intradermal nevus presenting as a skin-colored raised nodule on the scalp. © Springer Science+Business Media This photo shows a halo nevus surrounded by a ring of depigmented skin next to a nevus without a halo. DermPics/SCIENCE PHOTO LIBRARY This photo shows a blue nevus composed of dark pigmented cells (melanocytes). DermPics/SCIENCE PHOTO LIBRARY 