Differential diagnosis of atypical nevi and early melanomas is extremely difficult, as they can often have similar clinical and dermatoscopic characteristics. Therefore, one of the guidelines in identifying early melanoma can serve as the development of clinical and dermatoscopic changes that are detected during the dynamic monitoring of patients. However, dermatoscopic criteria that allow differentiation of atypical changing nevi from early melanomas in dynamics are not well investigated.

OBJECTIVE

A comparative assessment of clinical and dermatoscopic characteristics’ development in changing melanocytic nevi and cutaneous melanoma which had no suspicious features at initial examination.

MATERIAL AND METHODS

The study included clinical and dermatoscopic images of cutaneous melanoma (n=6) and melanocytic nevi (n=43) that developed changes during follow-up of patients at high risk of melanoma with sequential digital dermatoscopy. Inclusion criteria were the presence of at least 2 dermatoscopic images obtained with an interval of at least 2 months and verified histopathological diagnosis of the lesion. Comparison of absolute frequencies was carried out according to the Chi-square criterion. In case the frequencies were less than 5, a Chi-square with Yates correction was used. Differences were considered statistically significant at a confidence level below 0.05 (p<0.05).

RESULTS

When conducting a comparative analysis, it was found that in melanomas such dermatoscopic characteristics were more common: uneven pigment loss (p<0.017), the appearance of a gray pigment (p<0.000), the appearance of an island of the pigment network around the periphery (p<0.00); the appearance of globules (p<0.0016); decrease in the area of hyperpigmented structureless zones (p<0.000); an increase in the number of atypical vessels (p<0.000); the appearance of atypical vessels (p<0.006); the appearance of point vessels (p<0.000); the appearance of white stripes (p<0.000); the appearance of a skin pattern (p<0.000); the appearance of foci of the negative grid (p<0.000); the appearance of a milky red veil (p<0.000).

CONCLUSION

A number of dynamic changes in dermatoscopic structures have been identified, which serve as an indication for a referral of the patient to oncologist for examination to exclude melanoma.