Nodular malignant melanoma. Or maybe not?

Abstract

On histopathological examination, there was a wellcircumscribed epithelial proliferation of monomorphic cuboidal cells, with focal evidence of ductal differentiation (Fig. 2). In the lateral intraepidermal component, the proliferation was composed of similar cells with heavily pigmented cytoplasm, forming nests that were fairly well-demarcated from the adjacent keratinocytes (Fig. 3). Rare mitoses were seen, but there were no atypical mitotic figures or cytological atypia.