In the third edition of the book, The digital pathology, whole slide scanning, and artificial neural network are described in details in Chapter 19. Furthermore, there are several significant changes in different techniques, such as the polymerase chain reaction and next-generation sequencing, immunocytochemistry, and flow cytometry. In addition, the molecular pathology and immunocytochemistry of various tumors are highlighted in each chapter. Updated classification of the World Health Organization and International Academy of Cytologists in the urinary cytology, lung, breast, salivary gland, and lymph node have also been discussed.