In general, a benign mole is a small (less than 6 mm) macule or papule with a well-defined border and homogeneous beige or pink to dark brown pigment. They represent benign melanocytic growths.
Moles have a typical natural history. Early in life, moles often appear as flat, small, brown lesions and are termed “junctional nevi” because the nevus cells are at the junction of the epidermis and dermis. Over time, these moles enlarge and often become raised, reflecting the appearance of a dermal component, giving rise to “compound nevi” (Figure 6–1). Moles may darken and grow during pregnancy. As White patients enter their eighth decade, most moles have lost their junctional component and dark pigmentation as a result of normal senescence. At every stage of life, normal moles should be well demarcated, symmetric, and uniform in contour and color. Regular mole screening is not an evidence-based recommendation for all adults, although rates of screening continue to rise.
Benign, compound nevus on the back. (Reproduced with permission from Richard P. Usatine, MD, in Usatine RP, Smith MA, Mayeaux EJ Jr, Chumley H. The Color Atlas of Family Medicine, 2nd ed. McGraw-Hill, 2013.)
I. New and evolving concepts of melanocytic nevi and melanocytomas. Mod Pathol. 2020;33:1.