Elder and Elenitsas

 
"Architectural pattern features of importance in the diagnosis (of superficial spreading melanoma) include the large diameter of the lesions, poor circumscription (the last cells at the edge of the lesion tend to be small, single, and scattered), and asymmetry (one half of the lesion does not mirror the other half). The epidermis is irregularly thickened and thinned. Rather uniformly rounded, large melanocytes are scattered in a pagetoid pattern throughout the epidermis. The large cells lie predominantly in nests in the lower epidermis and singly in the upper epidermis. The nests tend to vary a good deal in size and shape, and to become confluent. Dermal melanophages and a dermal infiltrate are regularly present. The lymphocytic infiltrate is typically dense and bandlike, especially in invasive lesions. This contrasts with the patchy perivascular infiltrate of dysplastic nevi.
 
Cytologically, the lesional cells are rather uniform and have atypical, hyperchromatic nuclei and abundant cytoplasm containing varying amounts of melanin that often consists of small, "dusty"particles. The tumor cells are almost entirely devoid of dendrites. This uniform cytological atypia is of considerable diagnostic importance and contrasts with the random atypia of dysplastic nevi." Elder D, Elenitsas R. Benign pigmented lesions and malignant melanoma. In: Elder D. Lever's histopathology of the skin. 8th Edition. Philadelphia: Lippincott-Raven Publishers, 1997:657.
 

Brief Critique

 
Most of the criteria included here are like those advocated by Ackerman and, in general, are helpful in guiding a histopathologist to a specific diagnosis of melanoma. Unhelpful, however, is the notion adapted from Clark of "uniform cytologic atypia," which is a contradiction in terms (pleomorphism is the most important attribute of cytologic atypia and pleomorphism, by definition, cannot be uniform).