Book Review: Toxicologic Pathology for Non-Pathologists

At first glance, publication of a book review on a tome dedicated to introducing major toxicologic pathology concepts to non-pathologists in a journal focused on the professional practice of toxicologic pathology would seem to be a pointless endeavor. Nothing could be further from the truth. This concise volume (892 pp [plus 27 pp for index] for the hardcover offering) offers a succinct introduction to many key topics in the field. While designed to edify toxicologists, regulatory reviewers, and basic investigators, Toxicologic Pathology for Non-Pathologists harbors much of value for toxicologic pathologists at all levels, from novice to expert. The text is framed in 20 chapters arranged to provide an orderly tutorial in the field. Each chapter has been written by one or more recognized subject matter experts for that topic, most of whom built their toxicologic pathology careers through long stints in contract research organizations, industry, research laboratories (academic or government), and/or consulting. Chapters possess a wealth of fundamental information, images, and tables as well as bibliographies designed to provide a relevant set of additional readings on that topic. The scope is broad, covering basic pathology practices (4 chapters), key organ systems (13 chapters), and several special problems (3 chapters). A thorough reading of this book will greatly speed the professional development of entry-level toxicologic pathologists while the numerous figures and tables will allow more experienced practitioners to better communicate with non-pathologist team members. The 4 chapters on basic pathology practices afford a masterful introduction to the field. Chapter 1 (“Introduction to Toxicologic Pathology”) paired with Chapter 3 (“Routine and Special Techniques in Toxicologic Pathology”) ably define expected qualifications of toxicologic pathologists, the tools they employ in tissue collection and analysis (focusing on structural [anatomic pathology] methods including in situ chemical and molecular procedures), and principal challenges in data generation (e.g., severity grading) and interpretation (e.g., adversity decisions). Chapter 17 (“Principles of Toxicologic Clinical Pathology”) covers similar considerations as they apply to analysis of cell and fluid samples, emphasizing the impact of such factors as animal species, husbandry, and study design parameters on the quality of the final data set. Chapter 2 (“The Pathology Report, Peer Review, and Pathology Working Group”) effectively addresses the elements that need to be included, or at least pondered, in preparing an accurate, brief, and clear pathology report. Such documents are the raison d'être for the toxicologic pathology role on a study team, and Chapter 2 readily outlines basic findings, their implications, and means of producing the best possible report. The 13 organ system chapters are abridged but nevertheless valuable synopses of major toxicologic pathology information for each topic. These chapters seek—generally with good success—to describe foundational biology principles (gross and microscopic anatomy as well as biochemistry and physiology, as warranted); incidental background findings and common test article-related lesions (including their features and preferred terminology); and guidance regarding data interpretation and risk assessment. I was particularly impressed with the excellent diagrams in Chapter 4 (“Pathology of the Liver and Gallbladder”) and Chapter 9 (“Pathology of the Respiratory System”) showing tissue microanatomy and classic lesion patterns. The main criticism I have for these chapters is with the illustrations. Only 6 of the 13 chapters—6 (urinary system), 7 (nervous system), 11 (male and female reproductive systems and mammary gland), 12 (integumentary system), 13 (musculoskeletal tissues including teeth), and 16 (ear)—contain more than a few photomicrographs, and in most figures the tinctorial characteristics represent fair (at best) reproductions of the cell and tissue features as seen in a properly prepared hematoxylin and eosin (H&E)-stained tissue sections. This criticism is assuaged in large part by the availability of many recent publications that present harmonized diagnostic nomenclature with myriad wellstained microscopic images (which can be accessed freely at https://www.toxpath.org/inhand.asp#pubg) for the organ systems covered in these 13 chapters. The 3 special problems chapters are dedicated to carcinogenicity (Chapter 18), findings in juvenile animals (i.e., mammals, Chapter 19), and toxicologic pathology of non-mammalian species (Chapter 20). The carcinogenicity and juvenile animal chapters cover common findings through both descriptions and a fair number of well-chosen photomicrographs and also present major biological processes and their implications for test article exposure. The non-mammalian species chapter introduces birds, reptiles, amphibians, and fish as potential alternative vertebrate models for unusual toxicology questions like high-throughput carcinogenicity and developmental toxicity 1156614 TPXXXX10.1177/01926233231156614Toxicologic PathologyBook Review book-review2023