Current Histopathology – serie

It is hoped that this book may serve two purposes. felt that the resulting increase in size and expense of First it is intended for use at the bench. to help solve the book would not be justified. some of the problems of cell identification which The material was collected over many years and puzzle not only beginners. but even experienced we cannot individually acknowledge the great contri­ observers in the field of cytological diagnosis. Sec­ bution made by technical staff of the clinical cytology ondly we have reviewed the most significant previous laboratories who assisted the two authors to prepare publications. particularly those of the past 20 years. and stain the sl ides. Most of the electron micrographs so as to provide a source of reference. were made by or with the assistance of the late Denis Cytological diagnosis should not be isolated from W. Jerrome. and we are also grateful to Dr David histopathology. and many readers will regret the lack Ferguson for further help and advice with these. All of the immunocytochemical stains were done by Dr of cyto-histological correlation in our choice of photographs. Cells centrifuged out of suspension in Anna Ghosh. and Drs David Mason and Kevin Gatter pathological fluids bear very little resemblance to kindly commented on that part of the manuscript. their counterparts in tissue sections.

This comprehensive book, illustrated with over 700 colour pictures, addresses the subject of bone in internal medicine. It is based on biopsies of bone and first describes the normal range of physiological findings in iliac crest biopsies in young, middle-aged and elderly individuals. The book then deals systematically with the osseous disorders most frequently encountered in internal medicine, and some that would be considered in differential diagnosis. Numerous up-to-date references are included. The clinical applications of biopsies of bone are emphasized as well as their clinical interpretation; sections on histomorphometry and functional aspects of bone cells are also included. The book should be of particular interest to specialists in internal medicine, endocrinology, nephrology, haematology and oncology, as well as being a bench manual for the practising pathologist.

Needle biopsy of the liver is now an accepted procedure in most large hospitals, and surgeons and laparoscopists are more likely to biopsy the liver under direct vision than in the past. Consequently, increasing demands are being made on pathologists for rapid diagnosis. This full colour atlas provides a practical guide to the histopathological diagnosis of liver disorders, with particular emphasis on clinicopathological correlation and the need for the pathologist to be in full possession of all the available clinical information. Although containing over 350 colour illustrations, the book is more than just an atlas and each section includes a brief description of the main clinical and pathological features of the subject under discussion. For this second edition, many chapters have been rewritten - e.g. on viral hepatitis - and many new illustrations added. The book is intended for the practising and trainee pathologist and the clinician who performs liver biopsies, but will also be of value to postgraduates, residents and students in other branches of medicine.

A practical approach to problems commonly encountered in paediatric tumour diagnosis. It comprehensively covers a wide range of common and unusual entities. Over 300 full-colour illustrations are complemented by a text which is pragmatic and succinct. References have been carefully selected to reflect current thought and well-written reviews. New treatment strategies have led to considerable improvement in the salvage rate and prognosis in childhood neoplasia. Histological diagnosis in this area is fraught with problems and the demand invariably has been for a prompt and accurate histological reporting. The problems, although wide-ranging, are particularly manifest in the area of the small round-cell tumours which constitute an important proportion of paediatric cancers. This atlas should be valuable as a bench manual for the practising pathologist and as a study aid for the trainee. It should also be of interest to all oncologists and paediatricians.

Because of the topographic and pathophysiologic information obtained with contemporary neuroimaging techniques, CT and MR scanning now constitute the most important investigation in clinical neurology. In many instances of mass lesions, the images provide a reliable or near-definitive diagnosis, and make possible the accurate and even selective acquisition of biopsy samples. For pathologists and neuropathologists rendering a brain biopsy service, a basic knowledge of CT and MR scanning is now mandatory, and the objective of this atlas is to present the principles of neuroimaging through clinicopathological correlation. It contains a wide range of clinical material, with over 600 CT and MR images correlated with over 400 full-colour pathomorphological micrographs. A discussion of differential diagnosis is complemented by extensive references. Although aimed mainly at pathologists in neurosurgical practice, the atlas should also benefit neurosurgeons and radiologists, especially those in training.

In the last decade tremendous progress has been made in the diagnosis and treatment of tumours of the mediastinum. The use of immunohistochemistry, molecular biology, electron microscopy, CT and MRI, and a better knowledge of tumour markers, has made for better diagnosis, often without the need for biopsy, in many cases. This in turn has clarified the classification and thus the epidemiology of tumours of the mediastinum, and modern radiotherapy, chemotherapy and surgery has led to improved survival of patients at risk. With over 300 illustrations, mostly in full colour, and a well-referenced text, this atlas is aims to serve as a bench reference for the practising diagnostic pathologist and a study aid for the trainee, as well as a comprehensive source of reference for oncologists and surgeons.

Early diagnosis of parasitic diseases, especially of the opportunistic infections, is gaining importance daily and pathologists now have the chance to make rapid diagnoses of these disorders by examining tissues and body fluids. Though parasitic infections and infestations occur mainly in subtropical and tropical areas, they are increasingly imported into other areas, where the pathologist must be able to recognize them. This new full-colour atlas, containing over 500 photographs, many diagrams and tables, with extensive references and index, concentrates on histology, differential diagnosis and on the structure of parasitic elements such as eggs, larvae and adult worms, in and outside tissues. The atlas should be useful as a bench manual for the practising pathologists to keep by the microscope, as well as for physicians, surgeons, dermatologists and pathologists in training, and all those who are concerned with parasitic infections.

This atlas deals with conditions commonly encountered in the male genital tract. Whilst the majority of illustra­ tions are photomicrographs, photographs of macro­ scopic specimens are also used to illustrate important features in distinguishing different pathological con­ ditions. Special emphasis is placed on the small biopsy specimens obtained from prostate and testis in modern urological practice and the importance of clinico­ pathological co-operation in pathological practice is stressed. Recent advances in our knowledge of testicu­ lar tumours are discussed and illustrated. The text is not entirely descriptive and attempts to give an intellectual framework around which histopathological diagnosis in this field can be practised. A modest number of references are included; they have not been singled out as representing milestones in the development of our knowledge of these conditions - the choice has rather more centred upon recent reports from which a litera­ ture search can be mounted if required. The atlas in no way pretends to be an encyclopaedic reference of con­ ditions of the male genital tract but attempts to provide an up-to-date comprehensive discussion of the histo­ pathology of this system. Acknowledgements I am most grateful to Mr Keith Gordon for developing all the photomicrographs and to Mr Geoff Gilbert and his staff in the Audio-Visual Department of the City Hospital who took the majority of the macroscopic illustrations. I must particularly thank my secretary, Mrs Dorothy Clay­ ton, for typing and retyping my draft chapters and for deciphering my hieroglyphics.

Biopsy of the gastrointestinal tract has been revolution­ less busy) teaching hospital. These sort of techniques, which I confess interest me greatly because of the ized by the introduction of fibreoptics; the proximal additional information which they can yield when rightly reaches, as far as the second part of the duodenum, and chosen, are naturally linked with improved methods of the whole large bowel back to the caecum can now be tissue preservation in general, bearing in mind that the sampled under direct vision and multiple small biopsies need for special techniques often becomes apparent can be obtained. Only in the jejunum and ileum are there only when the biopsy has been conventionally still limitations on the sampling of localized as opposed to generalized conditions. The sheer volume of gastro­ processed and examined. However, I have firmly intestinal material passing through our own laboratories stabled this hobbyhorse and have included little that has risen steeply over the last years to form some 25% cannot be done in a district general hospital and nothing that I am not prepared to do myself. I have tried to of the total current work load and the rise continues; stress, particularly, common lesions which can cause nearly all of it is in biopsy form rather than as resected specimens.

The aim of this atlas is to illustrate the wide range of histological appearances which can be seen in brea. st biopsies and mastectomy specimens. An attempt has been made to include photomicrographs showing the more usual appearances as well as some of the unusual patterns encountered in most common lesions of the breast. In addition some of the rarer forms of mammary pathology have been illustrated, sometimes extensively, where this was considered important in the differential diagnosis and where photomicrographs of good quality were available. Some of the low power photomicro­ graphs lack detail but have been retained as they illustrate Important microanatomical or architectural patterns. The majority of the photomicrographs are of histological preparations stained with haematoxylin and eosin, buta few special stains have been used to illustrate certain specific features. Only occasional photographs of gross specimens have been included. This is notto belittle the importance of gross appearances: indeed micro­ scopic examination of any tissue should always be complemented by careful naked-eye examination. A few mammographic pictures have also been included to illustrate characteristic patterns. There are no photo­ micrographs of cytological preparations as these were considered outside the scope of this book and excellent atlases of mammary cytology already exist. It is hoped thatthisatlaswill prove useful to surgical pathologists and others interested in the histological appearances of the breast. It is not intended as a comprehensive study of breast diseases, and details of clinical presentation and treatment have only been mentioned briefly.

This book is intended as a practical bench manual phological abnormalities in renal diseases, and for the hospital pathologist who wishes to have where appropriate these have been illustrated. access to a simple informative account of renal Although the main emphasis is on the pathology, pathology, particularly for the interpretation of the relevant clinical aspects of the conditions cov­ percutaneous needle biopsy specimens. I n addition ered are included in recognition of the fact that we trust it will be valuable to physicians working renal disease is an area in which correlation of the in the field of renal disease, for whom the interpre­ clinical and histopathological findings is particularly tation of renal biopsy material is directly relevant to important in reaching an informed diagnosis. patient management. Whilst a comprehensive coverage more appro­ priate to a larger text has not been attempted, the Acknowledgements text has been planned to give an adequate account of the more important non-neoplastic disease pro­ We would like to thank the technical staff of the cesses and their pathological appearances in the Histopathology Laboratories of The London Hos­ kidney. Points of difficulty in interpretation and dif­ pital Medical College, The Hospital for Sick Chil­ ferential diagnosis are covered both in the text and in dren, Great Ormond Street, and Guy's Hospital the illustrations.

Because of the topographic and pathophysiologic information obtained with contemporary neuroimaging techniques, CT and MR scanning now constitute the most important investigation in clinical neurology. In many instances of mass lesions, the images provide a reliable or near-definitive diagnosis, and make possible the accurate and even selective acquisition of biopsy samples. For pathologists and neuropathologists rendering a brain biopsy service, a basic knowledge of CT and MR scanning is now mandatory, and the objective of this atlas is to present the principles of neuroimaging through clinicopathological correlation. It contains a wide range of clinical material, with over 600 CT and MR images correlated with over 400 full-colour pathomorphological micrographs. A full discussion of differential diagnosis is complemented by extensive references. Although aimed mainly at pathologists in neurosurgical practice, the atlas will also benefit neurosurgeons and radiologists, especially those in training.

Needle biopsy of the liver is now an accepted procedure in most large hospitals, and surgeons and laparoscopists are more likely to biopsy the liver under direct vision than in the past. Consequently, increasing demands are being made on pathologists for rapid diagnosis. This full colour atlas provides a practical guide to the histopathological diagnosis of liver disorders, with particular emphasis on clinicopathological correlation and the need for the pathologist to be in full possession of all the available clinical information. Although containing over 350 colour illustrations, the book is more than just an atlas and each section includes a brief description of the main clinical and pathological features of the subject under discussion. For this second edition, many chapters have been rewritten - e.g. on viral hepatitis - and many new illustrations added. The book is intended for the practising and trainee pathologist and the clinician who performs liver biopsies, but will also be of value to postgraduates, residents and students in other branches of medicine.

This comprehensive book, lavishly illustrated with over 700 colour pictures, addresses the subject of bone in internal medicine. It is based on biopsies of bone and first describes the normal range of physiological findings in iliac crest biopsies in young, middle-aged and elderly individuals.The book then deals systematically with the osseous disorders most frequently encountered in internal medicine, and some that would be considered in the differential diagnosis. Numerous up-to-date references are included. The clinical applications of biopsies of bone are emphasized as well as their clinical interpretation; sections on histomorphometry and functional aspects of bone cells are also included.The book will be of particular interest to specialists in internal medicine, endocrinology, nephrology, haematology and oncology, as well as being a bench manual for the practising pathologist.

Cancer is an important cause of death within the first 15 played an important role in assembling valuable data concerning some of the less common neoplasms. Such years of life. Many childhood cancers are fundamentally different from those arising in adults by virtue of patho­ sources of information, as well as those produced by large genesis, behaviour and response to therapy. One of the repositories of material (e.g. The American Armed Forces Institute of Pathology), are widely utilized throughout the great success stories of recent years has been the dramatic improvement in survival of children with many different text. types of cancer. This has been made possible largely is a field which is evolving fast on Paediatric neoplasia through the development and implementation of multimo­ several different fronts, and, against this backdrop, the dality treatment regimes, as well as increasingly accurate accompanying text can only provide a 'snapshot' account.

Early diagnosis of parasitic diseases, especially of the opportunistic infections, is gaining importance daily and pathologists now have the chance to make rapid diagnoses of these disorders by examining tissues and body fluids. Though parasitic infections and infestations occur mainly in subtropical and tropical areas, they are increasingly imported into other areas, where the pathologist must be able to recognize them. This new full-colour atlas, containing over 500 photographs, many diagrams and tables, with extensive references and index, concentrates on histology, differential diagnosis and on the structure of parasitic elements such as eggs, larvae and adult worms, in and outside tissues. The atlas will be invaluable as a bench manual for the practising pathologists to keep by the microscope, as well as for physicians, surgeons, dermatologists and pathologists in training, and all those who are concerned with parasitic infections.

In the last decade tremendous progress has been made in the diagnosis and treatment of tumours of the mediastinum. The use of immunohistochemistry, molecular biology, electron microscopy, CT and MRI, and a better knowledge of tumour markers, has made for better diagnosis, often without the need for biopsy, in many cases. This in turn has clarified the classification and thus the epidemiology of tumours of the mediastinum, and modern radiotherapy, chemotherapy and surgery has led to improved survival of patients at risk. With over 300 illustrations, mostly in full colour, and a well-referenced text, this atlas is an invaluable bench reference for the practising diagnostic pathologist and a study aid for the trainee, as well as a comprehensive source of reference for oncologists and surgeons.

Like all specialized areas of medicine, that of joint disease informative. The techniques, practical and interpretive, has become surrounded by a practical mystique and are highly reproducible and simple, allowing them to be applied in any laboratory. jargon specific to itself. The number of clinicians working Although we see this volume as being of value to all in the field is large but the number of pathologists small. interested in joint disease it is specifically aimed at It follows that the majority of pathologists are at somewhat laboratory staff wishing to offer a synovial fluid analytical of an immediate disadvantage when discussing and ana­ service. Like most cytology we believe much of the cell lysing articular problems with their rheumatological and and non-cell identification and quantitation can, and orthopaedic colleagues. should, be undertaken by trained technical staff. The book In the specific area of synovial fluid examination the is therefore aimed primarily at two groups: pathologists difficulties for the pathologist are compounded because who do not specialize in joint disease and technical staff to date there have been no basic texts that detail the who will be generating the data on which interpretation methods, findings and interpretation of the macroscopic will be based. It is therefore both a text book and a bench and microscopic characteristics of the fluid in the common reference manual. arthropathies. In this book we hope to go some way We do not believe our data or methodology represent towards rectifying this omission.

Examination of the bone marrow has always been, and to-date techniques whose application will undoubtedly to a large extent still is, within the domain of the haema­ increase in the future. tologist. This is because smears of bone marrow aspirates After lengthy discussions and enquiries, the conclusion together with peripheral blood films and results of other was reached that the magnifications of most of the tests and investigations provided the information on which illustrations could be omitted without detracting from the usefulness of the Atlas. The magnifications used are the clinical diagnosis was based. Recently, the widespread availability of both improved indicated in Fig. 1.25. In addition, not every detail specif­ biopsy needles and techniques for processing has greatly ically indicated in a figure or its legend is necessarily increased the number of routinely taken bone biopsies mentioned in the text; and often a range of observations and placed the examination of bone marrow biopsy is illustrated and in these cases the legends are self­ sectiors also in the field of histopathology - so that explanatory. this Atlas is one of the Current Histopathology series. This Atlas is directed to haematologists and to histo­ Therefore, the haematologist and the histopathologist pathologists and to anyone interested in the investigation now complement each other in the interpretation of bone and understanding of the human bone marrow. marrow smears, imprints and sections, thus utilizing all available information and expertise to arrive at a diagnosis.

Many pathologists have little acquaintance with ear, nose concomitant biopsy have become commonplace in the and throat pathology. Some receive few specimens from management of throat disorders. It is hoped that. by ENT tissues; others are deterred from deeper study of the publication of this Atlas, pathologists receiving only material that emanates from regions the normal anatomy occasional specimens will be guided in their provision of of which is so forbidding in its complexity and holds no a report helpful to the clinician and those who are involved familiarity through autopsy investigation, for, apart from with a larger ENT service may be providec with a guide the larynx, there is usually no compelling indication for to the deeper understanding of the subject. examination of the ear, nose or throat at postmortem. Yet. The modern tendency in publication of ristopatholog­ equally with biopsy specimens from other parts of the ical microphotographs is to omit any statement of their body, the pathologist's report is consequential for the magnification, since it will usually be clear to the reader efficient handling of ear, nose and throat illnesses and what order of enlargement is involved. I n this Atlas, sometimes even for the patient's survival.

It is hoped that this book may serve two purposes. felt that the resulting increase in size and expense of First it is intended for use at the bench. to help solve the book would not be justified. some of the problems of cell identification which The material was collected over many years and puzzle not only beginners. but even experienced we cannot individually acknowledge the great contri­ observers in the field of cytological diagnosis. Sec­ bution made by technical staff of the clinical cytology ondly we have reviewed the most significant previous laboratories who assisted the two authors to prepare publications. particularly those of the past 20 years. and stain the sl ides. Most of the electron micrographs so as to provide a source of reference. were made by or with the assistance of the late Denis Cytological diagnosis should not be isolated from W. Jerrome. and we are also grateful to Dr David histopathology. and many readers will regret the lack Ferguson for further help and advice with these. All of the immunocytochemical stains were done by Dr of cyto-histological correlation in our choice of photographs. Cells centrifuged out of suspension in Anna Ghosh. and Drs David Mason and Kevin Gatter pathological fluids bear very little resemblance to kindly commented on that part of the manuscript. their counterparts in tissue sections.

Our aim in producing a colour atlas of toxicological guidelines itemize the investigations to be carried out pathology was to present a catalogue of histopathologi­ during the course of the study and they normally include: cal lesions which we had encountered over the years in clinical observations and behaviour; food intake and body various laboratory animal species exposed to a vast weight measurements; serum biochemistry; haema­ range of pharmaceuticals, agrochemicals and industrial tology; ECG and ophthalmology. At the end of a study, chemicals. While we believe a colour atlas is the ideal full macroscopic and microscopic examinations of the way to share our experiences with others, it quickly organ weight analyses together with tissues are essen­ became clear to us that for the atlas to be meaningful tial. By far the greater part of the material used in this the associated text must be comprehensive and contain book is from toxicity studies conducted in recent years ample literature references. and performed in compliance with the Good Laboratory The atlas is intended for both the trainee and the Practice standards of governmental regulatory bodies in experienced toxicological pathologist working with lab­ Europe, Japan and North America. oratory animals in the pharmaceutical, agrochemical or Toxicity studies are commonly carried out in rats, chemical environment.

Pathology in general is closely linked with clinical medi- cardiographic changes may be desired and therefore a cine and in cardiovascular pathology this interdepend- short section has been included on cutting the heart ence is, perhaps, greater than in most other specialities. according to conventionally used echocardiographic In recent years great advances in investigatory proce- planes. dures have taken place, including the examination of The heart can only react to physiological changes or fresh endomyocardial tissue obtained by bioptome, per- damage in a limited way and therefore a separate chapter mitting not only clinico-pathological correlation but also on hypertrophy and dilatation and another chapter deal- examination at histochemical and ultrastructural levels. ing with changes in the endocardium, which reflect hae- Angiography has gained wider usage and two-dimen- modynamic alteration and may additionally show sional echocardiography is no longer the preserve of diagnostic features, are also included. Degeneration to- specialized units.Percutaneous coronary transluminal gether with changes in connective tissue and ischaemic angioplasty is a relatively new approach to relieving heart disease are separately presented. Atherogenesis, obstructive coronary artery disease. Cardiac pathology recognition of myocardial infarction and the earliest mor- has therefore moved apace, providing not only a back- phological changes discernible at histochemical and ground to clinical manifestations but also visual proof for ultrastructural levels of investigation, which are within other investigations such as immunology and virology. the scope of modern routine laboratories, are empha- Such investigations have played an essential role in sized.

Dermatopathology is both exciting and exasperating. tum corneum cells. This occurs in disorders of keratiniza­ Skin has an elegant simplicity in its functions yet a tion because the process of desquamation is disturbed (Figure 1. 1). ferocious complexity in its structure. This is one of the paradoxes that underly the pathology of skin disease Parakeratosis. The presence of nucleated horn cells in and may go some way in explaining the multitudinous the stratum corneum. Normally the horn cells (corneocy­ disorders to which the skin is subject. The ready visibility tes) are thin lamellae of less than 1 f. lm thickness. They of the skin may also help explain why straightforward contain no detectable cytoplasmic contents as these are histological examination cannot always provide an lost in the granular cell layer. Parakeratosis occurs when answer to a clinicians's question. Quite dramatic appear­ the process of keratinization is disturbed such as when ances may be due to alterations of the relative rates of the rate of epidermal cell production is increased (as in blood flow, with or without oedema, in the different psoriasis) so that nuclei are not broken down before the vascular plexuses or around different structures in the stratum corneum is reached and when damage occurs horizontal dimension, neither of which may result in to the upper epidermis (Figure 1. 2). 'much to see' histologically. The inherent sampling error Porokeratosis.

With the advent of enzyme histochemistry, which this field and simplistic theories will be expanded or revealed hitherto unseen pathological differences discarded. between muscle disorders, muscle biopsy assumed Diseased muscle cells, as any other cell type, show an important diagnostic role. The investigation is easily only limited morphological changes. However bizarre, performed and is being undertaken with increasing very few of these changes, if any, are pathognomonic of frequency. Nevertheless there is still a tendency to a single disease. The exact significance of microscopic regard its interpretation as highly specialized and out­ findings is to a large extent determined by their clinical side the province of the general histopathologist. In this context. Thus, although this is an atlas, it is definitely atlas I have tried to lift the veil of neuropathological not designed to promote 'spot' histological diagnoses. I mystique and to describe and illustrate the basic have aimed to provide a guide to pathological reactions reactions of muscle cells. of muscle which will be useful to the practising histo­ Interpretation of the biopsy depends not only upon pathologist and all students of neuro-muscular disease. recognition of morphological abnormalities, but upon I hope that recognition of the lack of specificity of understanding why they occur. Throughout the atlas I individual morphological features will encourage the have attempted to correlate morphological changes . close clinico-pathological correlation which is essential with pathogenetic mechanisms.

This atlas deals with conditions commonly encountered in the male genital tract. Whilst the majority of illustra­ tions are photomicrographs, photographs of macro­ scopic specimens are also used to illustrate important features in distinguishing different pathological con­ ditions. Special emphasis is placed on the small biopsy specimens obtained from prostate and testis in modern urological practice and the importance of clinico­ pathological co-operation in pathological practice is stressed. Recent advances in our knowledge of testicu­ lar tumours are discussed and illustrated. The text is not entirely descriptive and attempts to give an intellectual framework around which histopathological diagnosis in this field can be practised. A modest number of references are included; they have not been singled out as representing milestones in the development of our knowledge of these conditions - the choice has rather more centred upon recent reports from which a litera­ ture search can be mounted if required. The atlas in no way pretends to be an encyclopaedic reference of con­ ditions of the male genital tract but attempts to provide an up-to-date comprehensive discussion of the histo­ pathology of this system. Acknowledgements I am most grateful to Mr Keith Gordon for developing all the photomicrographs and to Mr Geoff Gilbert and his staff in the Audio-Visual Department of the City Hospital who took the majority of the macroscopic illustrations. I must particularly thank my secretary, Mrs Dorothy Clay­ ton, for typing and retyping my draft chapters and for deciphering my hieroglyphics.

This Atlas of Oral PathologV is intended primarily as a ances where appropriate and reproduce relevant radio­ graphs. Every pathologist who deals with bone specimens bench companion for the general diagnostic pathologist. especially the trainee. It has not been designed to cover will know the value of radiographs, and some indeed are the subject fully and in detail, nor does it enter into the reluctantto make a diagnosis in their absence. In addition, radiographs may give a good idea of the extent aFld other more theoretical aspects. Since the book is essentially an atlas the text has been features of a lesion that may be represented in the first kept to a minimum, but in it we have tried to adopt'a instance only by a small biopsy specimen. practical approach, with special regard to differential diag­ While many of the illustrations have been made from nosis. We have made some remarks about the clinical sections freshly cut and stained for the purpose, others features of the various conditions dealt with, since this have been prepared from stained sections already in our may help the pathologist to appreciate what is in the refer­ files and since, in addition, the material comes principally ring clinician's mind in an area with which the pathologist from two departments, as well as from outside sources, may not be particularly familiar.