Nevi, Melanocytic

Key Features

• Benign mole

  • Small (< 6 mm) lesion with a well-defined border

  • Single shade of pigment from beige or pink to dark brown

• Stages of nevi

  • First decade: junctional nevi are nevus cells are at the junction of the epidermis and dermis; appear as flat, small, brown lesions

  • Over next 2 decades: Compound nevi are moles that have enlarged and become raised, reflecting appearance of a dermal component

  • As white patients enter their eighth decade: most moles lose their junctional component and dark pigmentation

Clinical Findings

• Normal moles should be well-demarcated, symmetric, and uniform in contour and color

• May darken and grow during pregnancy

Diagnosis

• Physical examination must take precedence over the history

• Benign nevi must be differentiated from malignant melanomas

• Signs of melanoma can be remembered by the mnemonic: ABCDE with A = Asymmetry; B = Border irregularity; C = Color variegation; D = Diameter greater than 6 mm; E = Evolution

Treatment

• None required; benign moles have a normal natural history

• Regular mole screening is not an evidence-based recommendation for all adults although rates of such screening continue to rise

• Moles that are atypical in any fashion that suggests melanoma should be excised and submitted for pathologic examination