Clinical Reference / Dermatopathology: Practical & Conceptual / Apr – Jun 2004 | Vol. 10, No. 2 / Skin Pathology, 2nd edition, by David Weedon. London: Churchill Livingstone, 2002, 1158 pages

Skin Pathology, 2nd edition, by David Weedon. London: Churchill Livingstone, 2002, 1158 pages

Apr – Jun 2004 | Vol. 10, No. 2
Hurt, Mark A.; Milde, Petra; Nieland, Michael L.

Cover of the book

Fig. 1

Skin Pathology, 2nd edition, by David Weedon.

Reviewed by Michael L. Nieland, M.D.

The second edition of Weedon’s textbook of dermatopathology represents a significant expansion of the first edition published only five years previously. The organization of the text remains the same as in the original edition, but it has been enlarged greatly by the addition of new material and references. According to the publisher, over 7000 new references have been added for a total of nearly 22,000. The vast majority of the illustrations, almost all photomicrographs in color, have been retained, but they have been reproduced in the new edition on glossy paper of increased weight with considerable improvement in definition and color fidelity. According to the publisher, 305 new illustrations have been added for a total of 1,000. The book is attractively bound and in the new edition the margins and edges of the pages are color coded by chapter, a feature that facilitates finding one’s way in the text and/or returning to a subject of interest. Within chapters, section headings are shaded in color so as to assist comprehension of the organization of each chapter. Additionally, for each diagnostic entity, bold typefaces or italics separate clinical descriptions and/or pathogenesis from histopathology and electron microscopy. Clearly, a good deal of effort has been expended by the publisher, as well as by the author, to create a volume of aesthetic appeal, as well as of considerable scientific merit and practical utility.

A substantial portion of the text, not unexpectedly, is devoted to inflammatory dermatoses which Weedon feels can be best approached by reference to and recognition of “tissue reaction patterns,” of which there are six “major” and a number of “minor” patterns, followed by assessment of four patterns of distribution of inflammatory cells within the skin. He favors this “crude algorithmic” approach because he feels that most experienced dermatopathologists assess sections of tissue in this manner by quickly integrating the tissue reaction pattern and the inflammatory pattern simultaneously. This is a reasonable approach applicable to a great many diagnostic problems. In the case of real conundrums, the strict algorithmic step-wise approach may provide an additional assist in arriving at the correct diagnosis. Those familiar with the algorithmic patterns developed by A. Bernard Ackerman may initially have some difficulty adapting to Weedon’s modifications or recognizing the framework on which they are based. Broadly speaking, the diagnostic entities in Ackerman’s categories of “superficial and deep perivascular dermatitis” have been included in Weedon’s “lichenoid,” “psoriasiform” and “spongiotic” major tissue reaction patterns, his “nodular and diffuse dermatitis” corresponds more or less in Weedon’s schema to the “granulomatous” reaction pattern and Ackerman’s category of “vesicular and pustular dermatitis” has, in general, been subsumed by Weedon’s “vesiculobullous” reaction pattern. An additional modification of Weedon’s schema has been to place many of the entities in Ackerman’s category of “nodular and diffuse dermatitis” into his own “vasculopathic” reaction pattern, which includes not only true vasculitis, but also the urticarias, neutrophilic dermatoses, and the somewhat controversial entity, “chronic lymphocytic vasculitis.” The latter concept has been questioned by Ackerman et al. [1 ] because they believe no clinical entity can be defined or diagnosed prior to biopsy as a “lymphocytic vasculitis,” and that what is called “lymphocytic vasculitis” is nothing but an epiphenomenon. Further definition of the precise role of lymphocytes in producing tissue damage at the cellular and molecular levels may resolve the issue.

Weedon considers Ackerman’s categories of “folliculitis and perifolliculitis” and “panniculitis” to be “patterns of inflammation” rather than “major tissue reaction patterns” and readers searching for these subjects, including the category of “alopecia,” will not find them grouped with the inflammatory dermatoses, but in separate sections in another part of the book devoted to the dermis and subcutis. Also, major discussions of infectious diseases and infestations, whose diagnosis is integrated into the algorithmic approach, are removed to an entirely separate portion of the text, as are major discussions of non-lymphoid, lymphomatous, and leukemic cutaneous infiltrates.

In the preface to the second edition, Weedon indicated his “desire to produce a textbook of dermatopathology that is comprehensive, applicable to the daily practice of the subject, and which contains recent references from accessible journals that are relevant to dermatopathology.” In terms of comprehensiveness there are very few entities that have escaped inclusion. I noted omission of discussions of amalgam tattoo, irritation fibroma, “leukoplakia,” chalazion, and oncocytoma. While ocular and mucous membrane pathology have generally been considered beyond the scope of the usual dermatopathology textbook, these entities occasionally turn up in daily in dermatopathologic practice and they might be considered for inclusion in the next edition. The enormous wealth of information provided for the vast number of subjects included in the text plus the large number of new entities extensively referenced dwarfs these few, probably intentional, omissions.

Regarding Weedon’s second goal, I find the text very useful in daily practice. The microscopic descriptions are lucid and accurate, and undoubtedly reflect the fact that the author has deep personal familiarity with the entities that he describes. In comparison to textbooks that are directed principally toward residents and fellows, the author has, with a few exceptions, neither devoted a great deal of additional text to differential diagnosis by microscopy as such nor to algorithmic road-maps. On the other hand, the text is so well-organized and the microscopic descriptions are so well-written that once one has ‘landed’ in one or another major category, particularly among the inflammatory dermatoses, one should be able, when it is possible to do so, to make discriminations among entities that are related closely to one another. As one who has long wrestled with the problems of distinguishing one inflammatory dermatosis from another, I was gratified to read Weedon’s admission (p. 81) that “spongiotic psoriasis . . . can be very difficult to distinguish from other spongiotic processes” and to read his comment regarding pityriasis rubra pilaris that “the author has missed more cases of this disease (on the initial biopsy) than any other”(p. 84). Clearly, Dr. Weedon also has found that some dermatoses don’t always follow the rules.

Along the same lines, I was interested, additionally, to read his comments concerning progressive psoriasiform epidermal hyperplasia in nummular dermatitis (p. 107), the occasional difficulty distinguishing psoriasis from seborrheic dermatitis (p. 109), his view that atopic dermatitis is associated in its acute form with spongiosis and some spongiotic vesiculation (p. 110), and that chronic atopic dermatitis may share features of psoriasis as well as lichen simplex chronicus. I hope that in future editions Dr. Weedon will not refrain from offering additional comments, insights, and reflections of a personal nature based on his daily practice.

In the Preface to the Second Edition, Dr. Weedon again quotes Pasteur’s remark that we are “coming nearer and nearer to the very essence of phenomena” although as knowledge expands, complexity increases and that goal seems ever elusive. Nevertheless, the reader will be reminded of Pasteur’s comment throughout the text by Dr. Weedon’s detailed summaries of our present state of understanding of the structure of the epidermis in the introduction to “Disorders of Epidermal Maturation and Keratinization” and of the structure of the basement membrane zone in the introduction to “The Vesiculobullous Reaction Pattern.” His in-depth summaries of current knowledge of the biochemistry of collagen and elastin in sections of the book devoted to disorders of collagen and elastin are masterful. Throughout the text, whenever appropriate, summaries of biochemistry, immunochemistry, and molecular genetics are offered, with lavish recent references, to the reader. Dr. Weedon, however, presumes much of the reader, and he should consider adding a glossary of terms, or, at least, providing definitions in footnotes for some of the basic science terminology outside the scope of dermatopathology. Examples are such expressions as epitope, epitope spreading, allogeneic, signal transduction, downregulation, upregulation, heterodimer, knockout mice, gene exon, heterotrimeric, heterotypic fibrils and the like, some of which occur repeatedly in the text. Often the sense can be appreciated from the context, and it is truly admirable that Dr. Weedon can wield this complex terminology with such facility and integrate the basic science into the text in such depth. I am certain, though, that there are many like me who would appreciate a little assist to our comprehension. I would also urge Dr. Geoffrey Strutton, who contributed the excellent chapter on lymphomatous and leukemic infiltrates, to add in the next edition an expanded section on the basic science of the immune and hematopoietic systems, and especially on the normal structure and function of lymph nodes and the lymphatic system, to better prepare the reader who has to traverse this difficult area.

In the Preface, Dr. Weedon also stated that it was his strongly held view that “many clinical aspects are relevant” and that “so often, an absurd or irrelevant diagnosis can be made on a slide if it is interpreted in the absence of clinical history.” He has, therefore, included succinct clinical descriptions for all of the entities in the text. I detected, though, instances wherein a histopathologic entity did not seem to be logically placed in one of the tissue reaction patterns because it made little sense clinically. For example, should the acantholytic solar keratosis be mentioned among the suprabasalar vesiculobullous diseases? Do Bowen’s disease and clear-cell acanthoma really belong among inflammatory diseases comprising “The Psoriasiform Reaction Pattern?” Admittedly, there may be limited resemblance histopathologically between a lesion of Bowen’s disease and a lesion of psoriasis at low magnification or between a clear-cell acanthoma and a papule of psoriasis, but it would be unusual for an experienced clinician to offer a diagnosis of psoriasis for either entity. Far more often, true lesions of Bowen’s disease arrive with diagnoses of basal-cell carcinoma or seborrheic keratosis, but almost never with a diagnosis of psoriasis. Also, I have never encountered in my years of clinical office practice a vesicular solar keratosis.

Throughout the text Dr. Weedon generally acknowledges arenas of controversy in concept or classification, and offers his opinion one way or the other, as he should. Two areas of contention have been alluded to briefly already – does spongiotic dermatitis represent a manifestation of atopic dermatitis or is atopic dermatitis a manifestation of scratching and rubbing [2 ]? Are pityriasis lichenoides and Mucha-Habermann disease manifestations of “lymphocytic vasculitis” [1 ]? I would have preferred that Dr. Weedon adopt the term “infundibular” [3 ] or at least “epidermoid” when discussing that variety of cyst rather than “epidermal” because the vast majority of epithelial cysts are not implantation-derived. Also, I missed mention of the fact that many infundibular cysts contain hair shafts, as well as bacteria and even fungal elements, which may contribute to inflammation when cysts rupture. I would also suggest that in the next edition Dr. Weedon should once and for all eliminate the term “sebaceous” even as a synonym for trichilemmal (isthmus-catagen) cyst for the obvious reason that its derivation has nothing to do with the sebaceous gland. If major textbooks continue to enshrine outmoded terms like “sebaceous cyst” and “dysplastic nevus” (vide infra) such erroneous terminology may never disappear from the literature or common usage. I would like to suggest also that in the next edition the section on erythroderma be placed, from the point of view of classification of disease, more appropriately with psoriasis and with other disorders of which it may be a manifestation (drug eruptions, mycosis fungoides, other inflammatory dermatoses), or both. Placing erythroderma alongside relapsing polychrondritis and confluent and reticulated papillomatosis and other orphan entities in a chapter given to the Miscellaneous suggests mechanical problems inserting their discussion into the text or that they represent afterthoughts. Each of the entities in this ultra brief chapter could much more logically be placed elsewhere in the text and this chapter could then be eliminated entirely. After all, when so much thought has gone into developing an overarching classification of disease, a “miscellaneous” category seems like a flaw or anomaly in the overall concept!

There is one statement in Dr. Weedon’s book that surprised me, namely, his comment in regard to the so-called intraepidermal epithelioma of Jadassohn (p. 894) that “this is perhaps the most controversial entity in dermatopathology.” I thought this issue was settled decades ago. Surely, the most controversial entity in dermatopathology in the last quarter century, and perhaps in all of medicine, with far-reaching ramifications in terms of patient anxiety and the cost of medical care, has been that of the “dysplastic nevus,” a term that is unfortunately now in the public domain, judging by its mention in Sunday newspaper magazine supplements. More than ten years ago the National Institutes of Health, in its January 1992 Consensus Statement [4 ], urged discontinuance of the term “dysplastic nevus” because of the controversy surrounding its use, and the Statement emphasized that the use of “dysplastic nevus” as a histologic diagnosis as well as a clinical diagnosis is discouraged. Dr. Weedon devotes a modest section of his text to “Atypical Nevomelanocytic Lesions” of which the main exemplar is the “Dysplastic (Atypical, Clark’s Nevus).” Ackerman [5 ] has stated flatly that “Clark’s nevus,” as he and his coauthors originally defined and employ the term, “is not a synonym for dysplastic nevus,” an entity which has never been defined consistently and lucidly. Dr. Ackerman objects also to the synonym “atypical nevus” because all melanocytic nevi “are atypical in the sense that they are expressions of a pathologic process.” Dr. Weedon states that Dr. Ackerman used the term “Clark’s nevus” for a “nevus with architectural atypia in the form of a junctional shoulder extending beyond the dermal one,” but nowhere in the article cited by Dr. Weedon [6 ] does Dr. Ackerman make this statement or is architectural atypia even mentioned. In fact, Ackerman et al. [7 ] have stated that “We are as opposed to unfathomable terms such as architectural disorder and atypical mole as we are to DN [dysplastic nevus],” and elsewhere they have recommended “strict avoidance of the terms dysplasia . . . architectural atypia and architectural disorder” [8 ]. Annessi et al. [9 ] have demonstrated recently that clinical atypia correlates poorly with those features said to constitute “dysplasia” and they concluded that “the dysplastic nevus does not exist as a discrete clinico-pathologic entity.” Dr. Weedon states that “the diagnosis [of dysplastic nevus] survives because proponents for its continued use can still be found and because alternative designations and definitions lack general support” – not exactly a ringing endorsement for its inclusion in a textbook as a generally accepted entity. In fact, recent polls of dermatologists and dermatopathologists [10, 11 ] did not strongly support Dr. Weedon’s statement that “dysplastic (atypical, Clark’s) nevi are clinically distinctive nevi with characteristic histology and an increased risk of melanoma change.” Only “26.8% of respondents felt that all dysplastic nevi have a higher probability of developing into melanoma than ‘ordinary’ nevi do.” Moreover, “97.2% of respondents felt there is a significant controversy surrounding the clinical significance and treatment of dysplastic nevi” and the authors of these reports also noted that “although ten years have passed since the formulation of NIH recommended nomenclature, wide variation in terminology continues to exist.” It is my opinion that until, or unless, there is general agreement terminologically for lentiginous nevi, Clark’s nevi, and other benign superficial acquired, tardive congenital nevi, and “dysplastic nevi,” it would perhaps be best to follow Piepkorn’s [12 ] recommendation simply “to call dysplastic nevi what they were designated before the 1980s – namely junctional and compound nevi” and refer to the other types of nevi in the same way as well. I hope that in the next edition of this textbook Dr. Weedon will relegate the “dysplastic nevus” to footnote status only, if it deserves mention at all. The “dysplastic nevus” has been a long, dark, and blind alley for dermatopathology – and an episode that does not bring honor to the discipline.

For a book of its size, Weedon’s Skin Pathology (said to contain in excess of one million words) is remarkably free of typographical errors. For the purpose of assisting Dr. Weedon in a very small way to prepare the next edition I have enumerated a few of these errors in their corrected form (Table 1) :

Table 1 List of typographical errors to Skin Pathology, 2nd ed.

p. 18 A. Bernard Ackerman Column 1, Para 2, Line 3
p. 36 Civatte bodies Caption to Fig. 3.7
p. 79 lumina Column 1, Para 7, Line 16
p. 458 microcomedo Caption to Fig. 15.2
p. 597 lumina Column 1, Line 3
p. 598 Luminal (??), hemorrhage Caption to Fig. 21.4
p. 600 upper epidermis Column 2, Para 3, Line 2
p. 661 through, inflammatory Column 2, Para 1, Line 11
p. 766 solar lentigines Column 1, Para 2, Line 14
p. 804 lentigines Column 2, Para 4, Line 3
lentigines Column 2, Para 9, Line 1
p. 805 lentigines Column 1, Para 1, Line 4
lentigines Column 1, Para 2, Line 1
lentigines Column 1, Para 3, Line 11
lentigines Column 1, Para 4, Line 2
p. 807 lentigines Column 1, Para 7, Line 3
p. 835 in this S100 preparation Caption to Fig. 32.35
p. 860 onto the surface Column 2, Para 6, Line 3
p. 863 are uncommon Column 1, Para 3, Line 11
p. 865 differences from Column 1, Para 5, Line 3
comedo-like Column 1, Para 5, Line 6
comedo plugs Column 1, Para 6, Line 2
p. 866 onto the surface Column 2, Para 3, Line 2
p. 874 openings onto Column 1, Para 3, Line 3
p. 895 different from Column 2, Para 1, Line 2
p. 924 different from Column 1, Para 3, Line 2
p. 1097 mononorphous (not monotonous) Column 2, Para 4, Line 4
p. 1100 monomorphous Column 2, Para 4, Line 2
p. 1152 Unna’s, 807 Index, under nevus

Also, on p. 21, should not exocytosis include erythrocytes, as in Mucha-Habermann disease?

Some further comments should be made concerning the photomicrographs in the book. A few could be replaced. In Fig 8.23, I cannot detect any hemosiderin in the dermis. The complementary iron stain would be more instructive. I cannot see well the dermal changes in Fig. 8.27 (atrophic papulosis), nor can I see the epidermal changes in Fig. 9.4 (epidermolytic hyperkeratosis), nor the cornoid lamellae in Fig 9.9 (porokeratosis), nor granular parakeratosis in Fig 9.27, nor acanthosis in Fig 18.4. It also seems to me that Fig 31.24 is not a very characteristic picture of fibroepithelioma of Pinkus. Moreover, there are so many illustrations that could be added to the text that it suffers by comparison to other texts that are illustrated more richly. So many additional entities deserve illustration.

My only major complaint about this monumental text, possibly unanticipated by the author or by the publisher, is that it is excessively ponderous, and because of its size and weight, can only be perused while it rests on a table. Bedside reading is out of the question, as is reading in the conventional manner while holding the book in one’s lap. It is acceptable for Webster’s Unabridged Dictionary to rest on a dictionary table while one looks up a single word, but Dr. Weedon’s book deserves to be read at length and savored. Of course, it would be desirable to obviate for the reader the problem in a multi-volume text of selecting the wrong volume for locating a subject of interest, but this book could easily be reorganized into a color-coded multi-volume text, as has been the case with several other major textbooks of dermatology. When appropriately expanded with additional illustrations, Dr. Weedon’s text could easily double in size to several volumes, e.g., one for inflammatory dermatoses, one for tumors, etc.

Even at its present size and cost, possession of Weedon’s Skin Pathology is a must for anyone interested in dermatopathology, and all who labor in this field should he proud of Dr. Weedon’s accomplishment. This text inevitably will constitute the definitive general text in dermatopathology.

Michael L. Nieland, M.D., is a dermatopathologist with Quest Diagnostics Inc., located in Pittsburgh, Pennsylvania.

References (MLN)

1. Ackerman AB, Mones JM. Lymphocytic Vasculitis. In: Resolving Quandaries in Dermatology, Pathology and Dermatopathology. Ardor Scribendi, New York, 2001;239.

2. Ackerman AB et al. Atopic Dermatitis. In: Resolving Quandaries in Dermatology, Pathology and Dermatopathology. Philadelphia: Promethean Medical Press, Ltd., 1995;17.

3. Ackerman AB et al. Epidermal Cyst and Epidermoid Cyst? In: Resolving Quandaries in Dermatology, Pathology and Dermatopathology. Philadelphia: Promethean Medical Press, Ltd., 1995;107.

4. Consensus Statement. NIH Consensus Development Conference, Volume 10, Number 1. January 27-29, 1992.

5. Ackerman AB, Cerroni L, Kerl H. Pitfalls in Histologic Diagnosis of Malignant Melanoma. Malvern: Lea and Febiger, 1994;89.

6. Ackerman AB. Enough mysticism about dysplastic nevi! Dermatopathol: Pract & Conc 2001;7(1):86-8.

7. Ackerman AB, Massi D, and Nielson TA. Dysplastic Nevus: Atypical Mole or Typical Myth? Philadelphia: Ardor Scribendi, 1999;181.

8. Ackerman AB et al. Nuclear atypia, cytoplasmic atypia and architectural atypia. In: Resolving Quandaries in Dermatology, Pathology, and Dermatopathology. Philadelphia: Promethean Press, Ltd., 1995;205.

9. Annessi G et al. Correlation between clinical atypia and histologic dysplasia in acquired melanocytic nevi. J Am Acad Dermatol 2001;45:77-85.

10. Ming ME et al. There is wide variation among dermatopathologists and dermatologists regarding the clinical significance and proper treatment of dysplastic nevi. J Cutan Pathol 2003;30:75.

11. Shapiro M et al. Investigation of the nomenclature used for microscopically dysplastic nevi. J Cutan Pathol 2003;30:75.

12. Piepkorn MW. A Perspective on the Dysplastic Nevus Controversy. In: LeBoit PE (ed.). Malignant Melanoma and Melanocytic Neoplasms. Philadelphia: Hanley and Belfus, Inc., 1994;259.

Reviewed by Petra Milde, M.D.

It was a pleasure and a challenge to review David Weedon’s second edition of his book, Skin Pathology, a pleasure because the book is outstanding, and a challenge because this review cannot possibly be a critique of its scientific content because of the shear volume of it. I have to restrict my remarks to a few suggestions on form, and offer praise as I have done previously.

This textbook has won the Advanced Author Book Category of the Medical Society of London Medical Book Awards in 1998. The current version is actually the third edition. The book appeared first in 1992, titled The Skin, as one volume of Systemic Pathology, edited by W.St.C. Symmers. Weedon’s gigantic opus has long become the authorative single volume text in dermatopathology replacing classics such as Pinkus and Lever. In 1997 (reviewed by Heino Hügel [1 ] and Luis Requena [2 ]), and in 2002, Weedon undertook the colossal task of revising and completing new editions.

I had reviewed the 1992 edition The Skin with Dr. Ackerman [3 ] as part of a series of reviews “A critical analysis of textbooks of dermatopathology in historical perspective.” We found “Weedon’s text (to be) the most massive, the most current, and the most inclusive” of all the dermatopathology textbooks we had reviewed at that time, “in short, the most valuable contemporary textbook of dermatopathology . . .” This statement holds true today, and is even more justified now. It is exciting to see David Weedon’s textbook continue to mature, and despite the enormous accomplishments of the first edition, excel anew.

Skin Pathology continues to be a single authored book, with the exception of one chapter contributed by Geoffrey Strutton on “Cutaneous infiltrates – lymphomatous and leukemic.” Weedon has to be admired for having, as he himself states, “declined offers of assistance with the writing, preferring to keep an element of continuity and to avoid entities ‘slipping through the cracks,’ as inevitable occurs with multi-authored books.”

The book is considerably larger in size (30 x 27 x 7cm or 11.8 x 10.6 x 2.8in), heavier (11.5 lbs) and contains more pages (1158) than the prior editions. It is bound in hardcover like the previous ones, but the overall layout of the book has changed from classic shades in grey, black, and white in the 1992 edition, to a very attractive and practical layout, in which sections and chapters are labeled, and can be identified by their individual bright colors visible on the outside of the closed book, thereby allowing quick orientation and handling. At the beginning of each chapter a separate page is dedicated to an index of that chapter. When the book is opened, the color, number and title of the chapter are apparent in the left and right upper corner on each page, further helping a reader to navigate through this book.

A shortcoming of the prior version has been overcome by using high quality paper and a glossy coating. While pictures in the 1992 edition were small and in black and white, color photographs were introduced in the 1997 edition, but colors were off and often too pale, worsened further by the use of cheap paper. Although most of the original photographs are used again in the current edition, pictures are now crisp, pleasurable to look at, and the color of the vast majority of the close to 820 illustrations is just right and very close to what one would see through a microscope. But David Weedon also added a considerable number of new color photographs, often taken both at scanning and high magnification, facilitating the conveyance of essential diagnostic features, such as pattern and architecture. Examples are Fig. 5.16(A)+(B) Lymphomatoid contact dermatitis, Fig. 5.17(A)+(B) Nummular dermatitis, Fig. 5.20(A)+(B) Atopic dermatitis, Fig. 31.40(A)+(B) Subungual keratoacanthoma, Fig. 36.6(A)+(B) Leiomyosarcoma, and many more.

Weedon has maintained the overall organization and structure of his book into seven sections (Introduction, Tissue reaction patterns, The epidermis, The dermis and subcutis, The skin in systemic and miscellaneous diseases, Infections and infestations, and Tumors), and 41 chapters. The classification of inflammatory skin diseases into different “tissue reaction patterns” (The lichenoid, psoriasiform, spongiotic, vesiculobullous, granulomatous, and vasculopathic reaction patterns) also remains unchanged.

Helpful tables on essential diagnostic features of inflammatory or neoplastic diseases in a certain category of disease can be found in many chapters. These tables are not only great for refreshing one’s memory in daily practice but, I am sure, will be widely used to prepare for Board examinations. Similarly, the introductory chapter on “Diagnostic clues,” which includes “General helpful hints and cautions,” is fun to read and, indeed, helpful, both for students and practitioners.

Weedon’s book covers virtually every entity in dermatopathology; many which were described more recently were added in the new edition.

As before, each entity is introduced with a paragraph covering clinical aspects, the author affirming the importance of that as follows: “It is my strongly held view that many clinical aspects are relevant. So often, an absurd or irrelevant diagnosis can be made on a slide if it is interpreted in the absence of clinical history.” These paragraphs often include discussion of etiology, pathogenesis, and prognosis of the respective disorder. The description of histopathologic findings is both to the point and detailed. The discussion of rare variants and associations is more inclusive than in any other textbook I am aware of. Where appropriate, immunopathology and electron microscopy findings are discussed.

Weedon’s book is unparalleled as a resource for detailed, relevant, and current references. In fact, Weedon has updated the reference of this new edition, increasing it from about 10,000 in the 1992 edition, to close to 22,000 entries in the current edition. This makes the book an invaluable resource, and often eliminates the need to do searches of the literature, he having facilitated direct access to relevant publications.

Weedon is a master in presenting the subject matter in a scientific, analytical fashion, citing relevant findings and facts without imposing his own views. He often lays out existing diverging views regarding a certain subject matter, and states clearly when he presents his opinion.

The index of the 2002 edition is again meticulous and comprehensive.

As before, Weedon devotes a large part of his book to inflammatory dermatoses. The richly illustrated chapters on that subject and the detailed clinical information offer tremendous support in the course of daily diagnostic work. The section on “Infections and infestations” contains superb photomicrographs of various infectious agents and a plethora on diagnostic tips remains another strong component.

Many of the chapters were revised. For example, “Tumors of cutaneous appendages” was partially reorganized, and new entities were included, such as panfolliculoma, apocrine poroma, myoepithelioma, etc. In the chapter on “Vascular tumors,” originally contributed by Geoffrey Strutton, Weedon adopted a new and, in my view, better classification. Geoffrey Strutton himself updated the chapter on “Cutaneous infiltrates – lymphomatous and leukemic,” using current up-to-date lymphoma classifications. More examples could be listed.

Basically, I find it difficult to criticize anything in this outstanding work. Nevertheless, assuming and hoping that Dr. Weedon is already working on a 3rd edition of Skin Pathology, I have some suggestions.

Residents in pathology and dermatology sometimes are overwhelmed as they plunge with great enthusiasm into Weedon’s Skin Pathology, the preferred textbook in many training programs. I would like to propose a discussion on a few minor changes which might help beginners.

Weedon has dropped both an introductory chapter on histopathology of the skin and a short glossary, both present in the first edition. Although detailed descriptions of histopathology and definitions of terms can be found throughout the book in the respective chapters, I do think that having introductory chapters on histopathology and embryology at the outset of the book, and a glossary of terms giving definitions of important terms, would be very helpful.

The classification of the book was criticized before, and, remains somewhat confusing, primarily from a didactic vantage, in particular the classification of inflammatory diseases. In his introductory chapter Weedon says this: “The interpretation of many skin biopsies requires the identification and integration of two different, morphologic features – the tissue reaction pattern, and the pattern of inflammation. This is a crude algorithmic approach; more sophisticated ones usually hinder rather than enhance the ability to make a specific diagnosis.” He notes further that “Some dermatopathologists base their diagnostic approach on the inflammatory pattern, while others look first to see if the biopsy can be categorized into one of the ’tissue reactions’ and use the pattern of inflammation to further categorize the biopsy within each of these reaction patterns. In practice the experienced dermatopathologists sees these two aspects (tissue reaction pattern and inflammatory pattern) simultaneously, integrating them in a matter of seconds.”

This, Weedon’s organization of inflammatory diseases into major tissue reaction patterns, certainly is a pragmatic approach and successfully avoids elements of redundancy present in a more “sophisticated” algorithmic approach. That works perfectly well from a practical viewpoint and for more experienced dermatopathologists, who use the book primarily as a daily resource and for reference. For teaching purposes however, Weedon’s distinction of tissue reaction pattern and pattern of inflammation remains confusing and somewhat artificial, especially since it is not entirely followed through in the chapters on inflammatory diseases. Students often struggle to reconciliate Weedon’s classification and the algorithmic method based on patterns formed by inflammatory cells set forth by A.B. Ackerman in Histologic Diagnosis of Inflammatory Skin Diseases.

In the chapter on “Tumors of cutaneous appendages,” some basic criteria for diagnosis, for instance, how to distinguish benign from malignant neoplasm by silhouette, are missing. Criteria to define follicular, apocrine or eccrine differentiation, etc., would help to better understand adnexal neoplasms.

Similarly, the chapter on “Cutaneous infiltrates – lymphomatous and leukemic” by Geoffrey Strutton would benefit from a short introductory review of normal lymph node architecture. Although many definitions are given within the text, a separate glossary defining and illustrating basics terms such as centrocyte, centroblast, immunoblast, marginal zone and so forth would be useful. These terms have also not been integrated into the otherwise very rich index.

David Weedon, driven in his own words by his “obsessive personality,” not only excels in adding new references, but also in adding “new entities.” I wonder if in some instances it would not be better to place these “entities” under more generic headings, rather than treating them separately, at the same time retaining them listed in the index. Examples are “HAIR MATRIX CYST” (as an early stage of Pilomatrixoma? under PILOMATRIXOMA AND PILOMATRIX CARCINOMA), “PIGMENTED FOLLICULAR CYST” (as a variant of EPIDERMAL (INFUNDIBULAR) CYST), “MELANOCYTIC MATRICOMA” (as Matricoma under PILOMATRIXOMA AND PILOMATRIX CARCINOMA), “COMPOSITE HEMANGIOENDOTHELIOMA” (under HEMANGIOENDOTHELIOMA), etc.

I find the book difficult to carry around because of its extraordinary size and weight. Although I am not generally an advocate of computerization (I wished for example, Dermatopathology: Practical & Conceptual would still be available in print), I would love to see a CD version of Weedon’s textbook.

These observations of mine relate primarily to teaching. In the tradition of many great texts in general pathology, David Weedon’s primary purpose may not be the accommodation of beginners.

David Weedon certainly achieved his mission in a brilliant way and remains true to his goals defined in the preface of the third edition: “. . . to produce a textbook of dermatopathology that is comprehensive, applicable to the daily practice of the subject, and which contains recent references from accessible journals that are relevant to dermatopathology.”

Pathology of the Skin is an outstanding work and will continue to form future generations of dermatopathologists. It is hard to comprehend how one person alone can accomplish so much. I hope colleagues will support Dr. Weedon’s efforts in contributing by communicating potential additions and in correcting errors of which I have seen none.

I am an admirer of David Weedon’s work. I highly recommend Skin Pathology to the readers of this journal, and every student and practioner in the field of dermatology, pathology and dermatopathology. In my view it is among the best, if not the best, single volume dermatopathology textbook currently available. For the practicing dermatopathologist in particular, it is a must to have this book next to the microscope as a daily companion.

Petra Milde, M.D., is in private practice at Atlanta Dermatopathology in Atlanta, Georgia.

References (PM)

1. Hügel H. Book Review: Skin Pathology, by David Weedon, M.D. Dermatopathol: Pract & Conc 1999;5(3):276-78.

2. Requena L. Book Review: Skin Pathology, by David Weedon, M.D. Dermatopathol: Pract & Conc 1999;5(3):278-79.

3. Milde P, Ackerman AB. A critical analysis of textbooks of dermatopathology in historical perspective. Part 17: Weedon D. The Skin. Am J Dermatopathol 1995;17:97-103.

Dr. Weedon's replies:

I have read the reviewers” reports and my response is as follows:

I would like to thank Dr. Milde and Dr. Nieland for their kind and generous reviews and I note their criticisms. It is unlikely that I will do another edition (I am nearly 62!). I will refrain from entering the “dysplastic nevus” debate. There is no controversy in this part of the world.

David Weedon.

Editor's Note

I wish to thank both reviewers, Drs. Nieland and Milde, for providing thorough and thoughtful reviews of Dr. Weedon’s book, and for Dr. Weedon’s reply to them.

About 10 years ago, the editors of the Archives of Pathology and Laboratory Medicine asked me to write a brief review of Dr. Weedon’s 1st edition of Skin Pathology, the one that was the real first edition, Volume 9 of the Symmer Series of Systemic Pathology. This is some of what I had to say about it then:

“This reference work accomplishes three goals of a classic, authoritative text: it presents diagnostic concepts in terms of essentials, it is logically organized, and it is comprehensive. Largely a single-authored work produced by Dr. Weedon, it has uniformity and continuity that multiauthored texts often lack.”

I am able to make a similar statement of the 2002 version of Dr. Weedon’s book, Skin Pathology. However, my amazement at the effort today is even greater, because the book is more of everything: it is larger physically, it has more pages, it has more references, it has more photographs (in color now), and it includes more subjects.

Having been involved in writing a few chapters for books in the last few years, I have seen, firsthand, how difficult it is to keep up continuously on even one subject, much less an entire textbook of subjects. Yet, Dr. Weedon has done that, continuously, since the real first edition, through the “second” first edition, and, now, to the current edition, somehow keeping his sanity in the process!

The style of this book, as well as his prior editions, has been one of extracting the findings of others, similar to the method used by most authors of textbooks. I liken it to the reading of a newspaper; it delivers the facts, often without comment, of what has been reported in the literature. It is unstated, but implied, that he agrees with the findings of others unless otherwise stated explicitly.

Although I believe it impossible to summarize such a book in a short essay, I will say simply that a summary is unnecessary here. The book contains something for everyone, and it is often the first place I go to look for the essence of recent literature, especially on obscure topics. I do not consult it, however, for novel concepts or deep discussions of subjects because, for the most part, they are not to be found.

I also do not recommend it to residents in dermatology or pathology because of the encyclopedic nature of it, which I believe impossible to read as a textbook from cover to cover. It is a reference work and should be used as such.

That said, any dermatopathologist or general pathologist who spends his professional life behind a microscope, and who struggles with seemingly limitless diagnostic dilemmas, will find great comfort in this book, and will discover many delightful insights, made all the more interesting by Dr. Weedon’s intelligence and consistency.

Mark A. Hurt, M.D.

Book Review Editor

This section is edited by Mark A. Hurt, M.D., a dermatopathologist from Maryland Heights, Missouri. Contact section editor via email: markhurt@aol.com.