Table 1.

Significant histopathologic features of superficial spreading melanoma according to Price, Rywlin, and Ackermann 1976

Poor circumscription of the intraepidermal melanocytic component of the lesion with lateral extension of individual melanocytes

Increased number of melanocytes, solitary and in nests, within and above the epidermal basal-cell layer and within adnexal epithelium (pagetoid appearance)

Marked variation in size and shape of the melanocytic nests

Confluence of melanocytic nests rather than discrete nests.

Absence of maturation of melanocytes with descent into the dermis.

Melanocytes with nuclear atypia

Melanocytes in mitosis

Necrosis or degeneration of melanocytes