Surveillance of patients at high risk for cutaneous malignant melanoma using digital dermoscopy

Summary Background  Dermoscopy has improved the sensitivity and specificity of clinical diagnosis of melanoma from 60% to over 90%. However, in order not to miss melanoma a certain percentage of suspicious but benign lesions has to be excised. Objectives  To evaluate the dermoscopic changes and the rates of excision in benign melanocytic naevi and cutaneous malignant melanoma in long‐term follow‐up of high‐risk patients using digital dermoscopy. Methods  Digital dermoscopic images of 2015 atypical melanocytic naevi in 196 high‐risk patients were analysed retrospectively. Among others, the following data were collected for each naevus: changes in surface area, overall architecture, dermoscopic patterns and distribution of pigmentation. All tumours suspicious for melanoma or showing asymmetrical changes were excised. Results  During a median follow‐up time of 25 months 128 (6·4%) of all naevi showed changes in size or architecture. Eighty‐six per cent of all changes in patients who attended more than one visit were observed at the first follow‐up visit. Thirty‐three lesions showing changes were excised and two melanomas in situ and 31 melanocytic naevi were diagnosed. Conclusions  Follow‐up examinations using digital dermoscopy revealed unchanged morphology in the large majority of melanocytic naevi. Excisions were only performed in cases of asymmetrical growth, asymmetrical changes of pigmentation, or development of dermoscopic features indicative of melanoma. The ratio of 33 lesions excised in order to identify two melanomas in situ seems reasonable and may be further reduced in future.