Dermoscopic patterns of cutaneous melanoma metastases

Although the long experience acquired with the widespread use of dermoscopy has allowed the establishment of criteria for the recognition of benign and malignant skin lesions, very few data are available on cutaneous melanoma metastases. As the characteristic clinical aspects are multiform and even histological evaluation may sometimes be difficult, we have studied and characterized the patterns of cutaneous melanoma metastases in dermoscopy. In this paper, we report dermoscopic data on 130 histologically confirmed metastases observed in 32 patients affected by melanoma, with particular emphasis on dermoscopic features. Nine dermoscopic elements (homogeneous, saccular, amelanotic, polymorphic and vascular patterns, colour, perilesional erythema, pigmentary halo, peripheral grey spots) were studied in 130 cutaneous melanoma metastases and compared with those of 350 melanomas, 150 common naevi, 40 blue naevi, 40 haemangiomas and 50 basal cell carcinomas. The saccular and vascular patterns (especially polymorphic atypical vessels and winding vessels), as well as pigmentary halo and peripheral grey spots, seem to be the most significant elements suggestive of cutaneous melanoma metastases. The interest in and importance of the dermoscopic aspects of cutaneous melanoma metastases cannot be neglected if the American Joint Committee has determined that microsatellitosis and micrometastases are fundamental in the new TNM staging classification for cutaneous melanoma.