JOURNAL OF PATHOLOGY, VOL. 157: 157-1 59 (1 989)

HOW DO WE TEACH PATHOLOGY?

BRIDGING THE GAP BETWEEN THEORY AND PRACTICE

CHARLES JAMES KIRKPATRICK

Department of Pathology, Technical University of Aachen ( R WTH), F.R.G.

In discussions with medical students in the United Kingdom and the Federal Republic of Germany I have been made aware of two principal demands, which at first sight might seem irreconcilable-the desire for fundamental explanation of disease processes and the desire for clinical relevance. Academic pathology has always been proud of being at the interface between the basic biomedical sciences and the clinical disciplines. The rapidity with which both these areas are changing, and in particular the former, makes review of our teaching methods more and more imperative. I would like to raise a few important issues in the two main fields of our teaching ,endeavour-that of undergraduate and postgraduate medicine.

UNDERGRADUATE MEDICINE

Our understanding of disease is being increas- ingly influenced by advances in cell and molecular biology, as well as in biochemistry. The role of the academic pathologist in such endeavour is an essen- tial issue, but one which should be dealt with else- where. Our teaching of general pathology must, however, reflect this progress in the basic sciences, without compromising what we consider to be the identity of our speciality. However, the mere presen- tation of definitions followed by macroscopic and histological appearances must be regarded as no longer acceptable. For example, in teaching the sub- ject of necrosis, we must include discussion of reac- tive oxygen species and lipid peroxidation, or in dealing with the principles of atherosclerosis we must discuss topics such as arachidonic acid metabolites and platelet-derived growth factor, to mention but two pathogenetically important factors.

I am fully aware of the fact that presenting up-to- date lectures in general pathology is a massive task,

but one which is well worthwhile, not only for our own edification, but also to maintain the identity of pathology as the integrative subject between science and clinical medicine. Ultimately, presen- tation of facts which explain clinical appearances will aid our students in understanding and therefore remembering the diseases which we teach. If, in dis- cussing the inflammation associated with type I hypersensitivity reactions students are taught that sensitized mast cells release eosinophilic chemo- tactic factor of anaphylaxis (ECF-A), which attracts eosinophils to the focus of antigen-IgE reaction, they are more likely to remember the pattern of inflammatory cell infiltration, than if this fact, derived from cell biological studies, is omitted.

The above considerations concern what we teach in the lecture theatre. An essential adjunct to a scientifically based lecture course in general pathol- ogy is a laboratory course in histopathology. We are sometimes criticized for imposing histopathology on medical students, who for the most part are prob- ably not going to use a microscope in their later practice of medicine. Such histopathology courses should, however, be retained for (at least) two reasons. First, examination of slides of diseased organs should make the student more aware of the characteristics of disease and the problems associated with making diagnoses. Second, the task of histopathology contains the same elements as all forms of diagnostic activity, namely observation, correlation of collected facts with existing knowl- edge, and, finally, decision. This is therefore good preparation for clinical diagnostic activity on patients, which is what our critics constantly remind us of.

Turning to systematic pathology, I consider that four points require particular attention. First, in the lecture course more emphasis should be placed on pathophysiology . Thus, the systematic presentation of disease will tend to lose its ‘textbook’ appearance

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158 C. J. KIRKPATRICK

and become more problem-orientated. At the University of Ulm in Germany, a typical ‘lecture’ begins by the presentation of a mortuary case by a group of approximately seven students, each having a specific task, such as presentation of the case his- tory, clinical investigations, differential diagnosis, and post-mortem findings, both macroscopic and histological. This is followed by a commentary by a member of the pathology staff, who then gives a more detailed expose of the disease process(es) con- tained in the case. Clinical aspects and clinicopatho- logical correlations are then discussed by a member of the clinical staff as well as by the pathologist. This combined lecture form, in which clinician and path- ologist present different, yet complementary, aspects of diseases should leave the student in no doubt as to the relevance of pathology in medicine as a whole. This lecture form is then followed by a more conventional lecture, enabling systematic presentation of diseases, organ system for organ system.

Second, and this has been alluded to above, teach- ing in the mortuary must remain an integral component of our teaching curriculum. Whether the mortuary cases are written up and handed in for marking, or whether they are presented in case con- ferences before fellow students is irrelevant. The essential point is that the medical student learns to associate pathological findings with the clinical course, or, to put it another way, to correlate struc- ture with function, which is the quintessence of our diagnostic activity and an essential feature of pathophysiology .

Third, the routine histopathology laboratory must be considered as part of our teaching arena. Feedback from medical students who have com- pleted their pathology courses, both in Germany and in the U.K., makes it clear that many students regard our principal work as being in the mortuary!! This appalling misrepresentation of our role in the medical infrastructure is partly due to our failure to present the facts about surgical pathology. The excellent tutorial system in U.K. medical schools offers a ready forum to discuss a variety of cases, as well as visiting the laboratory from time to time. Other European countries, such as the Federal Republic of Germany, with gigantic medical schools (350 to over 500 students annually), must use the lecture theatre or audiovisual teaching laboratory to present this aspect of pathology. This becomes all the more important when we consider that more and more physicians are passing endoscopes and removing biopsy specimens for

histological examination. The ability of the student to understand the limitations of such investigations will in large measure determine the ability of the clinical colleague to appreciate what we write in our reports.

Fourth, the advances in therapeutic methods, whether they be in chemotherapy or intensive care medicine, are bringing the pathologist face to face with a new ‘generation’ of patient, namely, with underlying disease mingled with the complications of iatrogenic intervention. The gap which has devel- oped between classical textbook pathology and the face of disease seen in the ward and out-patient clinic requires to be bridged by courses dealing with iatrogenic pathology.

POSTGRADUATE MEDICINE

Many of the above-mentioned considerations are equally applicable to postgraduate medicine. Diag- nostic pathologists are very aware of the need to maintain a friendly and pragmatic dialogue with their clinical colleagues. Good working relation- ships at this level depend on continuing education of young colleagues embarking on their specialist training programmes. Nowhere is the need for unambiguous communication more acute than in the field of frozen section diagnosis. Yet, I wonder how many medical schools devote a lecture to this topic? As a practising pathologist, I have been shocked by the material sent by some colleagues, not all of whom are young and ‘inexperienced’. For example, small skin biopsies suspicious of malignant melanoma or small amounts of uterine curettings sometimes arrive with the request for frozen section diagnosis. That the primary diag- nosis should be made in formalin-fixed, paraffin- embedded material appears to have escaped the notice of the attending clinician. This is a topic which should find its place in both undergraduate and postgraduate teaching programmes. Further- more, from a psychological viewpoint, it is a much easier task to explain to a trainee surgeon than to a colleague of perhaps equal academic rank the limi- tations, indications, and contraindications of frozen section examination!

Finally, the continuing importance of the mortu- ary requires constant stressing, and not only to pro- vide us with much-needed teaching material, but in the interest of clinical training, which ultimately comes to bear on the patient. Good clinicians, self- critical and critical of diagnostic methodology and

HOW DO WE TEACH PATHOLOGY? 159

therapeutic regimes, require no prodding to see that their fatal cases come to post-mortem examination. It will remain a challenge to the pathologist to continue reminding the clinician of the relevance of this basic examination to clinical teaching and practice.

In conclusion, if we continue to regard our speciality as one which is in a constant state of flux, we will make the adjustments necessary to enable us to claim, modestly but with no need for defensive strategy, that we are indeed at the interface between science and medicine, between theory and practice.