Diagnostic effectiveness of dermoscopy performed by plastic surgery registrars trained in melanoma diagnosis

Background: Dermoscopy improves sensitivity and specificity and helps in the early detection of melanoma and nonmelanoma skin cancers (NMSC). Because of the multidisciplinary approach to melanoma, plastic surgeons may be required to perform dermoscopy evaluation. For this reason, in some university hospitals, plastic surgeons in training might perform these evaluations. To assess the validity of digital dermoscopy conducted by plastic surgery registrars, the authors collected the diagnoses of excised lesions from a dermoscopy outpatient clinic, comparing results with literature. Methods: A total of 1094 consecutive dermoscopy evaluations performed at Padova University Hospital between 2015 and 2018 were included in the study. All examinations were carried out by 3 plastic surgery registrars who received comparable training on dermoscopy. Excised lesions were classified according to pathological reports. Results: Four hundred sixty-six lesions were excised, and of them, 224 (48%) were considered pathological or atypical lesions: 34 melanomas (15%), 83 dysplastic or uncertain significance nevi (37%), and 107 NMSC and their precursors (48%). Considering only the 347 pigmented lesions, 34% were malignant or dysplastic lesions. The number needed to treat (NNT) was 10. The nevi-to-melanoma ratio (NMR) was 8, and the malignant melanoma-to-melanoma in situ ratio (MM:MMIS ratio) was 0.36. Conclusions: This retrospective study tested the performance of specifically trained plastic surgery registrars in the detection of malignant skin lesions. Compared to literature, the analysis reflects a good sensibility for melanoma, especially in early curable stages. Moreover, our study underlines quite a high number of total excisions, which could be explained by the “surgical imprinting” of plastic surgery registrars