This volume is the latest in a series of tumor classifications published by the World Health Organization. The previous 11 volumes were concerned with basic organ systems, such as the lungs, the breasts, the ovaries, the bladder, and the thyroid. Many are accepted as standard classifications by general pathologists for these organ systems were formulated in these volumes, and I have little doubt that pathologists will probably incorporate many of the concepts in this volume. The classification divides skin tumors into five main categories: epithelial tumors and tumor-like conditions, precancerous lesions and conditions, tumors and lesions of the melanocytic system, soft tissue tumors and tumor-like lesions, and tumors and tumor-like conditions of the hematopoietic and lymphoid "tissues" After a section of definitions and explanatory notes for each of these tumors can be found 176 half-page color illustrations, the quality of which is well above average. Also available is an alphabetical