Digital dermatoscopic follow-up of 1027 melanocytic lesions in 121 patients at risk of malignant melanoma.

Objective: The aim of the presented prospective study was to use a digital dermatoscopic system to follow-up patients with multiple melanocytic naevi, and to evaluate the frequency and character of dermatoscopic changes.

Methods: We monitored selected melanocytic lesions with the use of a 6-month follow-up interval between check-ups. We searched for changes in size, shape, symmetry, structure and colour. We defined the criteria for surgical excision and histopathological examination of changing lesions. We created a small group of excised unchanged atypical melanocytic naevi.

Results: We completed dermatoscopic monitoring of 1027 melanocytic lesions in 121 patients at risk of developing malignant melanoma. The average total follow-up interval was 21.0 months. We noticed a substantial enlargement of monitored lesions in 4.5% of cases, and there was a change of shape in 1.3% and change of asymmetry in 2.0%. The appearance of new structures, frequently being associated with malignant melanoma, was observed in 10 lesions, and it was predictive for the histopathological confirmation of this diagnosis in all cases. About 80% of monitored lesions remained unchanged. We excised 38 monitored lesions (seven melanomas in situ, four thin invasive melanomas and 27 melanocytic naevi). There was no melanoma excised in the group of unchanged atypical melanocytic lesions.

Conclusion: Digital dermatoscopic follow-up facilitates the recognition of thin malignant melanomas and helps to reduce the number of unnecessary excisions.