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.
An atypical mole is a melanocytic lesion characterized by asymmetry, border irregularity, color variegation, or diameter 6 mm or greater (Figures 1A, 2A, 3A, 4A, 5A, and 6A). Atypical moles usually appear between childhood and early adulthood, with an estimated incidence of 2% to 8%.1 They are more common in patients with fair skin and high cumulative sun exposure and are mostly found on sun-exposed skin.
SORT: KEY RECOMMENDATIONS FOR PRACTICE
| Clinical recommendation | Evidence rating | Comments |
|---|---|---|
| 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. Counseling should include strategies to reduce UV radiation exposure and the risk of developing skin cancer.18 | B | Systematic review with low to moderate-quality evidence |
| When used by a trained clinician in addition to visual inspection, dermoscopy, improves accuracy in diagnosing melanoma and aids in identifying suspicious skin lesions most concerning for melanoma.35,36 | B | Systematic reviews with moderate-quality evidence |
| Excisional biopsy with 1- to 3-mm circumferential margins and sufficient depth to avoid transecting the base should be performed for pigmented lesions suspicious for melanoma.47,49 | B | Retrospective cohort studies, consensus guideline |
| Routinely re-excising incompletely or narrowly excised atypical moles with mild or moderate atypia is not recommended.56 | B | Retrospective cohort study |
A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to https://www.aafp.org/afpsort.
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Incidence of atypical moles and melanoma is lower in people with skin of color (eg, individuals of Asian, African, Alaska Native, American Indian, Hispanic or Latino, Pacific Islander, or multiracial ancestry).2 In these populations, atypical moles are more likely to occur on non–sun-exposed skin, such as palms, soles, and nails (Figure 7A). This difference in anatomic distribution, combined with limited patient and physician awareness, may contribute to delayed diagnosis and worse outcomes.3
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