Classification of melanoma in adults and children.

After a brief history of the classification of melanoma in adults, this chapter describes the major features of the classic histogenetic types as well as of uncommon variants. Particular attention is paid to the meaning of controversial terms such as "minimal deviation" and "borderline." Specific problems associated with the classification of melanoma in children are also addressed, along with interpretation of atypical lesions resembling Spitz nevi.