Book excerpt: Based on Lever's Histopathology of the Skin, Ninth Edition, this full-color atlas presents an algorithmic pattern recognition approach to differential diagnosis of skin diseases. Whereas Lever's classifies diseases by pathogenesis, this atlas aids in differential diagnosis of unknown cases by classifying diseases morphologically, based on their location in the skin and the patterns and cell types seen through the microscope. Within each morphologic category, prototypic disorders are described and illustrated with full-color photomicrographs, and a list of differential diagnostic possibilities is presented. The atlas contains over 1,300 full-color illustrations. A bound-in image bank CD-ROM contains all the book's illustrations.