Kim CC, et al. - Researchers studied to evaluate the consequences and risk for the development of subsequent cutaneous melanoma (CM) from moderately dysplastic nevi with positive histologic margins and observed routine skin surveillance as a reasonable management. They also found an association between biopsied dysplastic nevi and an increased chance for subsequent CM at a separate site.

Methods

• Three years or more of follow-up data were collected consecutively from January 1, 1990, to August 31, 2014 in a multicenter (9 US academic dermatology sites) retrospective cohort study conducted on subjects with age 18 years or more, affected with moderately dysplastic nevi with positive histologic margins.
• Researchers analyzed the records for patient demographics, biopsy type, pathologic findings, and development of subsequent CM at the biopsy site or elsewhere on the body.
• They estimated the univariate relation for risk of subsequent CMs with χ² test, the Fisher exact test, and analysis of variance, in addition to multivariable logistic regression models.
• They confirmed the histologic grading with each site submitting 5 random representative slide cases for central dermatopathologic evaluation.
• They performed statistical analysis from October 1, 2017, to June 22, 2018.
• Development of CM at a biopsy site or elsewhere on the body were their main outcomes and measures where there were moderately dysplastic nevi with positive histologic margins.

Results

• They observed 467 moderately dysplastic nevi with positive histologic margins among 438 participants (193 women and 245 men; mean [SD] age, 46.7 [16.1] years).
• With a mean (SD) follow-up time of 6.9 (3.4) years, no cases were found developed into CM at biopsy sites.
• A sum of 100 cases (22.8%) was observed with developed CM at a separate site.
• The history of CM was significantly related to the risk of development of subsequent CM at a separate site (odds ratio, 11.74; 95% CI, 5.71-24.15; P < .001), as were prior biopsied dysplastic nevi (odds ratio, 2.55; 95% CI, 1.23-5.28; P=.01).
• They revealed agreement in 35 of 40 cases (87.5%) as the results of a central dermatopathologic review.
• Out of 40 cases, 3 were upgraded in degree of atypia and of these, 1 was rendered as melanoma in situ.
• After 5 years of follow-up, this subject was observed without recurrence or evidence of CM.