As in the second edition, the third edition of Handbook of Practical Immunohistochemistry Frequently Asked Questions is written in a question and answer (Q&A) format and intended to be a practical, user-friendly, quick reference for information related to using the most up-to-date immunohistochemistry and in situ hybridization in clinical diagnosis. The new edition demonstrates a significant revision and improvement over the second edition. Five new chapters have been added that cover the following: 1) Immunohistochemistry: Leica s perspective; 2) Immunohistochemistry: Maixin perspective; 3) RNA in situ hybridization: Applications in anatomic pathology; 4) Applications of rapid immunohistochemistry on frozen tissue sections during intraoperative pathologic diagnosis; and 5) Cutaneous lymphomas. In addition to extensive additions and changes, over 150 new questions and answers were added throughout this new edition.