Diagnostic performance of electrical impedance spectroscopy in patients with multiple nevi and large acquired nevi

Patients with atypical mole syndrome may benefit from screening methods that enable early melanoma detection and prevent unnecessary biopsies. Electrical impedance spectroscopy (EIS)'s utility in this patient population has not previously been reported. Therefore, we conducted a cross-sectional study of nevi in patients with atypical mole syndrome to characterize the EIS scores of clinically stable nevi in this patient population and to evaluate the test-retest reliability of EIS. EIS scores of selected clinically stable nevi were taken at an initial visit and 2-6-week follow-up visit. Patients invited for participation were aged ≥30 years, had ≥100 nevi, had at least 3 large acquired nevi >5 mm in diameter, and had baseline total body photographs obtained ≥3 years prior to initial visit. A total of 89.2% of large, 88.3% of atypical-appearing, and 65.0% of small nevi had false-positive EIS scores ≥4. Modest agreement was observed in test-retest reliability at 2-6-week follow-up with Bland-Altman 95% confidence interval of ±2.85. EIS and CASH (color, architecture, symmetry, and homogeneity) dermoscopy scores were positively associated (95% confidence interval = 0.11-0.25, P < .001). We conclude that EIS cannot indiscriminately be used in the screening evaluation of stable nevi in patients with atypical mole syndrome ; changes in EIS score <3 may not represent clinically significant change during short-term follow-up of stable nevi.