Digital dermoscopy in clinical practise: a three-centre analysis

Background: Early detection of cutaneous melanoma is the most important step to improve prognosis. In recent years objective techniques have been developed to improve diagnostics of pigmented lesions superior to the naked eye. Digital dermoscopy offers several advantages such as independence from the investigator, format ready for teledermatology and image storage, and comparability. Setting: In a routine setting including three centres in Europe, i.e. Lugano and Locarno in Switzerland, and Dresden in Germany, the usefulness of digital dermoscopy in daily routine has been evaluated. Patients and methods: Digital dermoscopy was performed with the DB-MIPS(C) system in 1308 patients, and 3544 pigmented lesions were evaluated. A total of 466 pigmented lesions were surgically removed and classified by histopathology. Among those 52 melanomas and 299 dysplastic, naevi could be identified. DB-MIPS(C) system evaluated 35 variables of geometrics, colour, colour distribution and texture. Lesion identification is realized by clustering. Another important part of the analysis was to study the decision making, i.e. removal or follow-up of lesions. The tendency to follow-up was defined as the ratio of (number of suspicious lesions-removed lesions)/suspicious lesions. The interventism is defined as the ratio of the number of removed lesions to the number of suspicious lesions. Results: The DB-MIPS(C) system was robust and easy in handling in daily routine. The data analysis and digital imaging were realized in real time. Fifty-two melanomas could be identified including eight in situ melanomas and 33 T1a melanomas (thinner than 1 mm). Sensitivity of digital dermoscopy varied between 90% and 95% between the three centres. Specificity varied between 79.6% and 93.3%. The centres differed in the patient population, the mean diameter of pigmented lesions and decisions. Interventism varied between 36.3% and 76.0%, follow-up varied from 24% to 63%. Higher levels of clinician's false positive were associated with a higher percentage of interventism. Conclusions: Digital dermoscopy offers advantages for daily routine in detection of early melanoma. Sensitivity and specificity for early melanomas is high and thereby, the experienced dermatologist can be easily supported in daily routine of a pigment lesion clinic to improve diagnostics and hopefully prognosis in cutaneous melanoma.