| Breadth usually >6 mm |
| Asymmetry |
| Poor circumscription; atypical melanocytes beyond the most peripheral discrete nest of melanocytes within the epidermis |
| Increased number of single atypical melanocytes within the epidermis and epithelial structures of adnexa and, in some foci, single melanocytes predominate over nests of them |
| Melanocytes scattered in the upper reaches of the epidermis |
| Variation in the size and shape of nests of melanocytes |
| Nests of melanocytes are not equidistant |
| Irregular shapes of nests of melanocytes |
| Tendency of nests of melanocytes to confluence |
| Failure of maturation of atypical melanocytes, with progressive descent into the dermis |
| Asymmetrical, patchy distribution of melanin within the neoplasm |
| Extension of atypical melanocytes far down the epithelial structures of the adnexa |
| Asymmetrical distribution of inflammatory cell infiltrates of variable densities at the base of the neoplasm |