Dermatopathology_FINAL.qxd 2/14/06 11:19 AM Page i Practical Veterinary Dermatopathology for the Small Animal Clinician Sonya V. Bettenay, BVSc Dip. Ed, MACVSc, FACVSc CSU Diagnostic Laboratory Dermatopathology Service Department of Clinical Sciences Colorado State University Fort Collins, CO Ann M. Hargis, DVM, MS Diplomate, ACVP DermatoDiagnostics, Edmonds, WA Department of Comparative Medicine University of Washington, Seattle, WA Phoenix Central Laboratory Everett, WA Jackson,Wyoming www.veterinarywire.com Teton NewMedia Teton NewMedia 90 East Simpson, Suite 110 Jackson, WY 83001 © 2003 by Tenton NewMedia Exclusive worldwide distribution by CRC Press an imprint of Taylor & Francis Group, an Informa business Version Date: 20140103 International Standard Book Number-13: 978-1-4822-4128-0 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources. 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Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com and the Teton NewMedia Web site at www.tetonnewmedia.com Dermatopathology_FINAL.qxd 2/14/06 11:19 AM Page iii iii Table of Contents Guide to Using This Book. ix 1 Biopsy Collection:Why, When, Where and How . 1 Biopsy Sample Selection. 2 Why and When to Collect a Biopsy Sample . 2 Where to Collect a Biopsy Sample . 2 How to Collect a Biopsy Sample. 4 Biopsy Sample Fixation . 13 Standard Fixation Techniques . 13 Fixation for Suspected Immune Mediated Skin Diseases . 14 Fixation for Selected Tumor Studies or for Selected Infectious Agents . 14 Clinical History . 15 Sample Shipment . 15 Microscopic Interpretation of a Biopsy Sample . 16 Limitations of Dermatopathology . 18 Value of Referral to or Consultation with a Dermatology Specialist . 18 Ancillary Procedures to Facilitate Diagnosis . 18 Common Errors of Sample Collection and Submission . 19 2 Clinical Lesion Definitions, Recommended Methods of Biopsy Sampling, and Representative Histologic Lesions. 21 3 Histopathologic Responses of the Skin to Injury . 53 Histopathologic Responses of the Epidermis to Injury . 54 Histopathologic Responses of the Dermis and Vessels to Injury . 76 Histopathologic Responses of the Adnexa to Injury . 90 Histopathologic Responses the Panniculus (Subcutis) to Injury . 102 4 Tumors and Tumor-like Masses of the Skin. 107 Tumors of the Skin . 109 Epidermis . 115 Adnexa. 121 Dermis, Vasculature, Nerve Tissue, Subcutis . 129 Bone Marrow Derived Cells. 137 Dermatopathology_FINAL.qxd 2/14/06 11:19 AM Page iv iv Practical Veterinary Dermatopathology for the Small Animal Clinician Tumor-like Masses of the Skin . 144 Cysts. 144 Hamartomas. 148 Other Tumor-like Lesions . 154 5 Laboratory Techniques for Tissue Processing and Staining 159 Sample Arrival at the Laboratory . 160 Gross Evaluation and Trimming of Sample . 160 Sample and Request Review . 160 Sample Trimming. 161 Tissue Demineralization. 161 Tissue Processing and Histochemical Staining Techniques . 162 Immunostaining Techniques (Direct Immunohistochemistry and Immunofluorescence) for Autoimmune Skin Disease. 165 Immunohistochemical Staining Techniques for Tumor and Tumor-like Conditions . 167 Immunohistochemical Staining Techniques for Infectious Agents. 168 Other Techniques . 168 6 Glossary . 169 7 Differential Diagnosis of Clinical Lesions and Lesions in Selected Anatomic Locations . 177 Appendices . 185 A. Dermatopathology Submission Form. 186 B. Suppliers . 187 C. Case Review . 189 Recommended Readings . 195 Index . 197 Dermatopathology_FINAL.qxd 2/14/06 11:19 AM Page v v Acknowledgements I dedicate this book to my parents, Gwen and Ron, and their partners Bill and Lois. They gave me the early opportunities in life and encouragement that allowed me to pursue my career. Practical Veterinary Dermatopathology is an attempt to make what I have learned in dermatopathology over the past decade available in a format for veterinarians to use on a daily basis. I hope this book enables a better understanding of the underlying basis of dermatologic disease, special techniques in biopsy sampling and interpretation of dermatopathology reports, and so ultimately benefits patients. Many people have supported and influenced me throughout my dermatology career thank-you to all of you, but especially Peter Ihrke. With specific regard to this book I would like to thank; Ken Mason, Graeme Mason, and Abe Dorevich for instilling the love of dermatopathology during my dermatology residency, Claudia von Tscharner-who was the catalyst for my career path change, David Robson, and my dear friend Helen Power for their incisive editorial comments, and Ann Hargis, my co-author who was also one of my mentors and without whom this would have been a very different book. I would also like to acknowledge the unconditional support of my husband, Ralf Mueller. Aside from being a truly wonderful partner, he is also an awesome critic. Finally thank-you to Carroll Cann and Nicki Giandomenico at Teton NewMedia for encouraging and guiding me with this, my first book. I will be allocating a portion of the profits of this book to research in the area of dermatopathology. Sonya V. Bettenay I acknowledge the family, friends, mentors, practitioners, and students who made the writing of this book possible, and the animals that gave me a reason to write. Ann M. Hargis This page intentionally left blank Dermatopathology_FINAL.qxd 2/14/06 11:19 AM Page vii vii Preface The process of learning dermatopathology is long and often bewildering. This book is designed to facilitate that process for the practitioner in small animal medicine, residents in veterinary pathology and dermatology training programs, veterinary students, and veterinary pathologists in general practice. The book is also designed to be used as an aid to interpretation of skin biopsy reports. We have included tables and lists to enable busy practitioners to reference selected material quickly and efficiently. The section on biopsy collection techniques is designed to improve knowledge of sample collection, handling, and submission for the ultimate purpose of establishing a specific diagnosis or differential diagnoses list for a skin disorder, and to emphasize the critical role the clinical history plays in histopathologic lesion interpretation and in establishing a specific diagnosis by the dermatopathologist. Two relatively new techniques to veterinary dermatopathology, the nail bed (claw bed) punch biopsy technique and the pinnal shave biopsy technique, are described. The section on clinical lesion morphology is designed to help correlate clinical and histologic lesions and help practitioners select the biopsy technique most likely to provide a diagnostic biopsy sample for a variety of clinical lesions (e.g., epidermal collarette, pustule, alopecia). The correlation of clinical and