Age distribution of Spitz nevus vs malignant melanoma

To compare the age distribution of Spitz nevus and melanoma among routine specimens in a dermatopathology practice, we conducted the following study. Methods. A computer search was performed of all specimens diagnosed by one of us (P.E.S.) during a 4-year period from May 1990 through June 1994 at the Yale Dermatopathology Laboratory, School of Medicine, New Haven, Conn. Of these approximately 50 000 specimens, all cases coded as Spitz nevus or melanoma were reviewed. Spitz nevi were defined as melanocytic nevi with a predominance of cells containing large nuclei and spindled or epithelioid shapes; not included were cellular blue nevi, deep penetrating nevi, and nevi that have been designated as dysplastic because of the presence of cells with abundant, finely granular brown cytoplasm. The majority of specimens were submitted by private clinicians (predominantly dermatologists) practicing outside the university. Only 2% of Spitz nevi and 3% of melanomas were submitted from