Atypical Moles

Atypical moles are melanocytic lesions that clinically present with asymmetry, border irregularity, color variegation, or diameter 6 mm or greater. They are more common in patients with fair skin and high cumulative sun exposure. High mole density (more than 100) and presence of atypical moles are associated with increased risk of melanoma and should prompt periodic, systematic skin examinations. The US Preventive Services Task Force recommends patient or parent counseling for individuals with fair skin who are 6 months to 24 years of age on sun protection to reduce skin cancer risk and selective counseling for adults older than 24 years with fair skin and certain risk factors. To distinguish benign moles from melanoma, clinicians should use the ugly duckling assessment and ABCDE (asymmetry, border irregularity, color unevenness, diameter 6 mm or greater, evolution) mnemonic during clinical examination, incorporating dermoscopy if appropriately trained. Biopsy is sometimes necessary to exclude melanoma. Excisional biopsy should include 1- to 3-mm circumferential margins and sufficient depth. Postbiopsy management is guided by the degree of histopathologic atypia determined by the dermatopathologist, margin involvement, and patient risk factors.