Preface

Dr. Jack Moulton would be very pleased that his book is in its fifth edition. He would welcome the return of color: it was present in the first edition in 1961. The quality of images between editions is not to be compared, but it is interesting and enlightening to compare old color and B&W images of the same tumors and leukemias with current images. The names of many tumors have changed and subtypes have emerged as we uncovered more about their true identity and behavior, at least with present day techniques. This will happen in every edition and is a credit to diagnosticians and investigators around the world. Past and present authors are part of the group that produced these discoveries. The present authors have summarized and detailed this body of information for pathologists, oncologists, molecular biologists, cancer biology investigators, veterinarians, and students of veterinary medicine. The authors have provided exquisite color images or created collages that pictorialize diagnostic features, pathogenesis, and techniques. Some images correlate radiographic, MRI, or CT studies with gross and histologic lesions, while others depict immunohistochemical, molecular, or cytological characteristics. Images provided by colleagues from around the world greatly improved this book, and their contributions are credited in legends. I hope readers note these contributors and realize how much the authors and I appreciate their willingness to share their expertise in pathology and photography. Images are an integral part of this book and pathology; they summarize and capture what words attempt to describe.

Technology and its application are responsible for much of the new information in all disciplines. The authors have done an excellent job of blending core, basic pathological tenets that will remain constant with new information uncovered by evolving technology. There are new authors, new chapters, and a tremendous volume of new information that is cited, reviewed, and summarized in a reader-friendly and practical manner. However, an evaluation of contents is the job of readers and reviewers, not of an editor proud of the book and friend of the contributors. I am proud of the contents because of the quality of work that authors so willingly gave for so little material reward. When you see them at meetings please thank them - it will mean more coming from you than me. The value of this book is due to their hard work in each chapter and throughout their productive careers. I am greatly indebted and thankful to them, as shall be our colleagues and patients in our clinics.

The book remains focused on diagnostics, biologic behavior of animal cancers, and oncogenesis. An overview of all the tumors within each body system is provided via text, tables, and images. This feature is why books still have value in the age of on-line everything. Authors also provided insights on how they differentiate tumors that appear histologically similar. Because of the desire to treat cancer in pets it is a reality that journal publications and a large component of this book are now focused on dogs and cats. Accurate morphological diagnoses and determination of prognostic parameters are required for the selection among numerous treatment modalities currently available. Although accurate tumor diagnosis and classification often requires multiple techniques, histopathology and cytology remain the foundation of diagnostics. Authors have integrated the growing body of discovery with the practical components of our work. Providing prognostic information based on histological findings is an expected part of pathologists' assessments but this text has not delved into treatment options as clinical oncology rewrites these approaches weekly. Often, clinicians value margin assessment as much or more than the diagnosis. There is a chapter dedicated to this topic and trimming biopsy specimens for histologic examination.

Tumor cytology has been added and will continue to expand in subsequent editions. For many tumors, cytology is as accurate as histopathology, can be used at patient side with minimal invasiveness, and can yield specimens for molecular studies. Grading schemes based on cytology and molecular profiles will be included in future editions. Cytological evaluation can replace biopsy for some osseous tumors, and if treatments beyond excision or palliative measures are not a consideration, then cytology can provide a final diagnosis for many solid tumors and most leukemias. Reference texts in the tissue and cytological diagnostic arenas are largely divorced, and integration of these can benefit morphological assessments of cancer disease. Furthermore, cytological assessment permits rapid turnaround time and will become same day when representative cytological images are sent from patient side to pathologists.

Immunohistochemistry is now a routine part of our diagnostic evaluation and a chapter is dedicated to this topic. Authors emphasize it is only one part of the diagnostic puzzle. IHC, PARR, molecular signatures, and other ancillary tests must be integrated with all the other data available; they are not stand-alone tests. We need these tests most when the interpretation of light microscopy is not straightforward, yet that is when ancillary tests may also be ambiguous. We should convince clinicians of this and we need standardization of methods. The tsunami of molecular diagnostics has not yet washed away H&E. Molecular tools to create signatures that differentiate tumors, detect cancers at the earliest possible intervention, elucidate oncogenesis, or become independent prognosticators are exciting developments. In addition to the molecular characteristics of tumors, the next generation of prognostic tools will look at the host's ability to respond to cancers. It is likely that the host's response will be as or more predictive of biologic behavior for many tumors than is assessment of margins, mitotic counts or immunohistochemical profiles. It will be terrific when tests identify whether a patient is likely to develop cancer, which cancer is likely, which treatment is best, and how innovative techniques (e.g., CRISPR) can be directed to treat the cancer. Cost accountability will always be a component of veterinary diagnostics and care.

I doubt reviewers will find much controversy in this book. There may be some diagnoses or a pathogenesis that others may not accept, but not many. If anything is controversial it may be in the appendices, where I tried to summarize information so it can be easily found and used. However, without standards for the diagnostic parameters to predict behavior or standardization of the techniques used, it is difficult to compare studies or merge data from different reports. Users are encouraged to read the original references for the many excellent details they provide.

We need standardization of diagnoses, techniques, and our follow-up assessments in veterinary oncology and oncologic pathology. Some would say this book is the standard with which to diagnose cancers in domestic animals. However, the techniques used to provide diagnoses need standardization, such as antibodies, primers, margins, areas in which mitotic figures are counted, and flow cytometry. Without standards for the diagnosis and techniques employed we cannot reliably compare results between studies and contradictions of prevalence, biological behavior, and diagnosis will continue. Standardization of outcome assessments is imperative, yet it may be the weakest link in the connection of histologic, cytologic, and molecular parameters with prognosis. Documentation of tumor recurrence with histopathological confirmation and autopsy data is essential to assess a tumor's biological behavior. Unfortunately the number of published case series reported with autopsy and histopathology is abysmally small. If veterinarians want to rely on information from investigative studies to help owners and their pets, they need to help collect accurate follow-up data. We need to train our new veterinarians that, in addition to being competent surgeons, clinicians, and caregivers, they have a responsibility to serve the profession as clinical scientists too.

All of us are indebted to mentors. They taught us, they nurtured our passion for pathology and were role models for each new generation of veterinary pathologists. The authors and readers of this book double-scoped and learned from some of the founders of veterinary pathology, and I dedicate this book to mentors. Many are icons in our disciplines but many of us benefitted enormously from hard-working and committed teachers who were not so widely known, but were essential to us. If I listed names I would forget some and offend others so please take a moment to think about those individuals who shaped you and your career. We all remain responsible for passing on this mantle.

We have not defeated cancer. That stated goal from many years ago did not acknowledge the complex biology of cancer. No one could have predicted the information about cancer would grow to the enormity it has. Despite all the time, money and great minds that have investigated cancer it remains a leading cause of death in animals and people. The discipline of oncology will expand in human and veterinary medicine and professionals from both disciplines should work together to understand how cancers develop and how to better fight them. Veterinarians, physicians, and researchers need a book like the one Dr. Moulton envisioned. This book would not be a reality without Wiley and the executive editor, Erica Judisch, and the freelance project manager Nik Prowse. An unseen person who helped throughout was Laura Cullins; she solved the...