Diameter guideline for skin lesions useful in detecting cutaneous melanoma

When selecting atypical lesions for skin biopsy, the diameter guideline of larger than 6 mm, or the D criterion of the ABCDE criteria, is a useful parameter and should continue to be used, according to researchers.

Researchers from various U.S. sites conducted a cohort study of 1,323 patients with 1,657 pigmented skin lesions suggestive of melanoma undergoing biopsies in dermatology hospital-based clinics and community practices. They aimed to assess the efficacy of the current guideline of larger than 6 mm in diameter for early cutaneous melanoma diagnosis to determine whether it should be adjusted downward to 5 mm.

Using a computerized imaging system, the researchers found that 853 (51.5%) of the lesions were 6 mm or smaller. Thirteen of those lesions (1.5%) were invasive melanomas. Of 804 lesions larger than 6 mm, 41 (5.1%) were invasive melanomas.

Twenty-two lesions (2.6%) of those 6 mm and smaller were diagnosed as in situ melanoma and 62 (7.7%) of those larger than 6 mm were also in situ melanoma. – by Stacey L. Adams

Arch Dermatol. 2008;144:469-474.