CDKN2A and MC1R variants influence dermoscopic and confocal features of benign melanocytic lesions in multiple melanoma patients

Non-invasive diagnostic tools are effective in the histomorphological study of melanocytic lesions. The role of melanoma susceptibility genes on melanocytic nevi histopathological features is not clear. The current study aimed to correlate genetic alterations and histomorphological features of melanocytic nevi. Clinical, dermoscopic and confocal features of 34 multiple melanoma patients and 34 controls were compared. Among patients with melanoma, carriers of CDKN2A mutations and/or MC1R variants, and wild-type genes were also compared. In patients with melanoma, a lighter phototype (P = 0.051), a higher number of nevi (P < 0.01) and clinically atypical nevi (P < 0.01) were observed. At dermoscopy, these nevi showed a complex pattern (P = 0.011), atypical network (P = 0.018) and irregular pigmentation (P = 0.037); at confocal, an irregular meshwork pattern (P = 0.026) with atypical nests (P = 0.016) and an inflammatory infiltrate (P = 0.048) were observed. Among patients with melanoma genetically tested, CDKN2A G101W mutation carriers were more frequently younger (P = 0.023), with clinically atypical nevi (P = 0.050), with cytological atypia (P = 0.033) at confocal. G101W mutation and MC1R variants carriers showed hypopigmented nevi (P = 0.002) and, at confocal, roundish cells infiltrating the junction (P = 0.019). These data suggest an influence of CDKN2A mutation and MC1R variants in the development of dysplastic melanocytic lesions. Non-invasive histomorphological evaluation, together with genetic studies, improves melanoma risk identification and early diagnosis, for a patient-tailored management.