Farmer and Hood

 
"Melanoma in situ is defined by asymmetric, irregular growth of atypical melanocytes that are confined to the epidermis. This proliferation begins at the dermoepidermal junction, resulting in contiguous atypical melanocytes that may remain confined to the dermoepidermal junction or may involve the hair follicle epithelium or sweat duct epithelium. Atypical melanocytes then migrate above the basal cell layer either singly or in small nests and are present at all layers of the epidermis including the granular cell layer. The epidermis may be hyperplastic or retain its normal configuration, or, at times, the rete pegs may be flattened. The melanocytes themselves may have a variety of shapes that include small and cuboidal, epithelioid or spindled, or varying combinations of these. There is usually a brisk inflammatory cell response consisting of patchy aggregates of lymphocytes and melanophages in the papillary dermis and scant fibroplasia." (Fig. 10) Farmer ER, Hood AF. Pathology of the skin. 2nd Edition. New York: McGraw-Hill Companies, Inc., 2000:1137.

View Figure  		Fig. 10   Our diagnosis and comment: Melanoma in situ.The statement that "the cells are more numerous than the variably atypical melanocytes characteristic of melanocytic dysplasia" is dizzying because melanocytes in so-called dysplastic nevus are not atypical (nuclei of melanocytes in that kind of nevus are small, oval, and monomorphous), and melanocytic dysplasia has yet to be defined in a comprehensible, repeatable fashion. In short, melanocytic dysplasia is irrelevant to the melanoma in situ pictured here. "Melanocytic dysplasia" is for 2001 what "junctional activity" was for 1953.
 

Brief Critique

 
Although the authors utilize silhouette as a route to specific diagnosis of melanoma and differentiation of it from nevi of various kinds that simulate melanoma histopathologically, chief among them Spitz's nevus, they do not mention a variety of important findings that pertain to architectural pattern, such as poor circumscription, uneven base, uneven distribution of melanin, and predominance of solitary melanocytes over nests of melanocytes in some high power fields within the epidermis and within epithelial structures of adnexa. They do, however, include attributes of melanoma like asymmetry and pagetoid pattern. Most of the attributes referred to, however, are not differentiating from those met in many examples of Spitz's nevus.