Abstract
Chapter 1 or Introduction consists of a discussion of basics of histological evaluation, including a definition of the target audience for the book and distinction between histology and histopathology. It contains examples of some microscopic images, and there is an interesting section on the reasons to become a pathologist, which I will address later in this review. It also has a discussion on the similarity of histological sections to a film, where the clues as discovered as the film evolves and the difficulties in interpretations of the data. Missing in this section is some discussion of sampling, which is pivotal in the approach to pathology, and the need to have the samples represent the whole. It briefly introduces staining methods, and finally, it presents, with examples, the process of defining how to reach a diagnosis.
Chapter 2 is an Introduction to Histopathology, in which the authors give a primmer of general pathology, with some examples and helpful images, starting with responses to injury, through acute and chronic inflammation and hypertrophy, hyperplasia, metaplasia, and then neoplasia, both benign and malignant.
Chapter 3 deals with the light microscope and provides a very good explanation of the optics of the microscope, with excellent explanations of the physics of focusing, including the role of the condenser, and finally a very short discussion of the fluorescence microscope. This section could be more complete by including discussion of diffraction as it is used commonly in histopathology, the use of polarized light for identification of certain features, and perhaps inclusion of the optics of confocal microscopy.
Chapter 4 titled “How to Examine Histological Sections” is mostly a short introduction to histology with emphasis in a couple of tissues, with a couple of helpful tables about how to distinguish specific tissues, and then a short section of step-by-step directions on how to examine the tissues, with a final brief description of artifacts. This chapter would have benefitted from a more complete presentation of different artifacts that occur as a consequence of processing. This would be extremely useful for the target audience to learn what artifacts are common and to understand how to avoid them.
Chapters 5, 6, and 7 constitute the core of the book and the most useful information for the target audience as well as for other professionals who are interested in understanding how tissue preparation occurs in a regular basis. Chapter 5 begins with a thorough examination of the basic principles, mechanics, and complications of fixation and ends with preparation for embedding. Chapter 6 starts with the embedding in paraffin, continues with sectioning, which contains an excellent discussion of the mechanics of the microtome, orientation of the microtome blade, and a listing of issues that can go wrong with the sectioning to end with a thorough examination of frozen sections. Chapter 7 is a very thorough explanation of the process of staining the sections, starting with the chemistry involved in hematoxylin and eosin staining and finishing with an explanation of representative common techniques for special staining. Because of the detailed directions and the inclusion of occasions when the stains may not work so well, this section is perhaps the most useful for pathologists as well.
Chapter 8 is a short discussion of the basis for histological staining, which explains some of the complications in using dyes. Chapter 9 is also a short discussion on histochemistry. Although there are some good basic ideas, the whole field is too vast for this book and therefore this should be considered a primmer for this technique.
The book is not intended to train pathologists but to give some helpful hints to toxicologists, particularly in their formative years on how histology works. As such it is a valuable resource. The Introduction deals with some generalities and is meant to show the reader some of the complications of histopathological evaluations. There are some good examples of the complications in histological evaluations, although the common issue of sample adequacy, a basic problem with histological evaluations, is not adequately addressed. The section on Introduction to Histopathology covers much ground in a succinct fashion and should be very useful to the audience in mind. It is factual and well organized. The section on the microscope is extensive and well written and should be useful to beginning pathologists as well as toxicologists and would be a good reference section to all interested in this field. The section on how to examine histological sections contains a concise table on the morphologic characteristics of certain tissues that is well-designed and a useful reference to all. The sections on fixation, embedding, sectioning, and staining are very well developed and would serve well not only for toxicologists but also for pathologists and technicians in training. The section on theoretical bases of fixation as well as the one on histochemistry are well worth a read for all interested in this subject, as they are factual and erudite in general.
This book would have benefitted from some discussion on the utility of electron microscopy for the evaluation of toxic effects of compounds, educating the audience in what is involved in preparing the samples as well as what are the conditions under which it is useful. Equally, I would have appreciated seeing some examples of artifacts that are commonly present in toxicological pathology.
The authors use the terminology “histopathologist” where some would prefer to have the term be “toxicologic pathologist”; although the former term is common in the United Kingdom, other countries would prefer the latter. In the Introduction, there is a curious discussion about what motivates toxicologic pathologists and whether pathology is a science, the author seems to think that the role of pathology is the collections of data. This section is highly speculative and not supported by evidence of any kind and therefore not useful. By providing diagnoses, the pathologist is not merely describing the changes observed but providing an educated decision on what is going on in the patient’s tissues, and providing a hypothesis for the reasons why this is occurring, as well as explaining why a specific change is not a number of alternative diagnoses. This constitutes an important starting point for the research effort. In summary, this book is a valuable resource for training toxicologists, pathologists, and technicians, and it will be a good addition to one’s reference library.