5.1.1 Melanoma-specific criteria
Atypical pigment network：Brown-black network with irregular meshes and irregularly distributed lines of different thickness（high specificity for the diagnosis of melanoma）.
Irregular dots and/or globules：Brown-black or gray，dots and globules of different size，irregularly distributed within the lesion.
Irregular blotches：Black，brown，or gray areas with irregular shape and/or distribution.
Irregular streaks and/or pseudopods：Radial lines irregularly distributed at the periphery of the lesion（streaks），sometimes with a bulbous projection at their peripheral ending（pseudopods）.
Regression structures：Melanoma with regression structures appears in the flat area of the lesion and may exhibit as either white scarlike areas corresponding to fibrosis or bluegray areas（peppering）corresponding to melanophages.(https://www.daowen.com)
Blue-white veil：Melanoma with blue-white veil appears in the elevated part of the lesion，which is blue-gray or blue-white，diffuse and irregular pigmentation.
Irregular vascular structures：Polymorphous vessels，coexistence of dotted，linear，or hairpin vessels in the same lesion.
Due to the specific skin anatomy，pigmented melanocytic lesions on the certain locations（face，palms，soles，and nails）show unique dermoscopic features.