Examination of dermoscopic and pathological findings of melanocytic lesions in patients under adjuvant systemic melanoma therapy

Melanoma, consisting approximately 1% of all skin cancers, is responsible for about 80% of deaths due to skin cancer. The long-standing IFN-α treatment in melanoma has recently given way to targeted therapies and immunotherapies. There is an increased cutaneous side effects caused by these agents. It is also known that these agents have effect on melanocytic nevi. This study aimed to investigate the dermoscopic and histopathological changes in melanocytic nevi in melanoma patientstaking adjuvant systemic therapy. For this purpose, images of 1299 melanocytic nevi from 25 melanoma patients undergoing adjuvant systemic therapy were evaluated before and after treatment. The histopathological features of 129 excised melanocytic nevi from 67 melanoma patients who have taken adjuvant systemic therapy or not were examined in their clinical follow-up. Melanoma patients who have taken targeted therapy have a more frequent reduction in global pigmentation and disappearance in pigment network of their melanocytic nevi compared with patients taking IFN-α and immunotherapy(p=0.000 ve p=0.000). In melanoma patients who have taken IFN-α treatment, atypical changes in the pigment network were more common in melanocytic nevi compared to those have taken targeted therapy and immunotherapy(p=0.003). According to histopathological findings; structural atypia, cytological atypia, inflammation, and fibroplasia are more common in excised melanocytic nevi of patients under adjuvant systemic therapy(p=0.003, p=0.004, p<0.001 ve p=0.020). Histopathological findings may be related with dermoscopic changes developing during adjuvant therapy. Dermoscopic and histopathological findings should be carefully interpreted by clinicians and pathologists during the follow-up of melanoma patients and new diagnoses and treatment decisions should be made taking these into consideration.