This volume follows the long tradition of AFIP Atlases of Tumor Pathology. The authors have put emphasis on diagnosis, so the presentation is generally concise, yet more comprehensive on key points. In addition, the authors emphasize diagnostically important information on immunohistochemistry and molecular genetics, and include additional details when biologically significant. Site-specific soft tissue entities covered in the other atlases are often excluded due to space constraints. The text is aimed as a practical diagnostic aid for pathologists, cytopathologists and pathology trainees, but the authors hope that their clinical colleagues and others may also find it as a useful source of information on soft tissue tumors and tumor-like lesions.