Understanding Pathology: From Disease Mechanism to Clinical Practice

Jeremy Jass

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9789057024689
• eBook ISBN: 9781000150896
• Edition: 1
• Topic: Medicine
• Subtopic: Gynecology, Obstetrics & Midwifery

This book shows how the discipline of pathology fits into society and interfaces with science and medicine. It focuses on anatomical pathology and covers the practice of laboratory medicine in the clinical setting. The book is helpful for health professionals, especially anatomical pathologist.

— PART I —
ANATOMICAL PATHOLOGY
An Evolving and Integrating Discipline

— 1 —

THE ORIGIN AND NATURE OF PATHOLOGY

Knowledge of the past and of the places of the earth is the nourishment of the mind of man

Leonardo da Vinci

What is the use of history?

The word pathology, derived from the Greek rootspathos (suffering) and logos (word), means the study of disease. Pathology has therefore been a subject of great and widespread interest throughout history, though the professional pathologist has existed for little more than a century and a half. This may seem surprising, since pathologists are closely linked with human dissection which has been carried out for many centuries.

GRAECO-ROMAN PERIOD

The natural philosophers of ancient Greece carried out human dissection and possibly human vivisection in Alexandria. However, their interest was more in philosophy than medicine, seeking the answer to the command of the Delphic oracle: ‘Know thyself. In Roman times, the body was considered sacrosanct and human dissection was neither permitted nor carried out (despite the opportunities afforded by the mutilated remains of gladiatorial combat). Galen (c. 130–201) was born in Pergamum in Asia Minor, studied medicine in Alexandria and practised in Rome, where he became the greatest physician of the age. He wrote of the internal structure of the human body as though he had undertaken dissection himself. However, his words were based on the instruction he had received from his teachers in Alexandria and his personal dissections of animals such as pigs and monkeys. Nevertheless his writings were to become enshrined as the absolute truth on human anatomy until the intervention of Vesalius in the sixteenth century. Galen’s views on the cause of disease were the same as those of the Greeks, a holistic belief based on the imbalance of the four humours: yellow bile, black bile, blood and phlegm (Nutton, 1993). Variants of this belief persisted through to the nineteenth century (Maulitz, 1993).

THE MIDDLE AGES

Human dissection began again in the late Middle Ages at the University of Bologna. Canon law permitted the careful external examination of corpses to determine whether inflicted wounds were likely to be the cause of death. During the papacy of Innocent III (1198–1216), it was decreed that a cadaver should be examined by two surgeons and a physician to establish if an earlier blow (inflicted by a bishop during mass) was responsible for the victim’s death (Crawford, 1993). By the end of the thirteenth century human dissection for legal reasons was accepted practice in Bologna and this paved the way for the anatomists. The first to undertake human dissection for the purposes of anatomical demonstration was Mondino de Luzzi (c.1275–1326), publishing his Anathomia in 1316. He was assisted by two women, Allesandra Gillani and Anna Morandi Mahzolini, who prepared wax models and casts of human organs as educational aids. Within the University of Bologna considerable authority was invested in the students themselves. Should medical students succeed in ‘obtaining’ a body they were entitled to insist that it be dissected there and then. The history of grave-robbing can be traced back to the Middle Ages.

Dissection was eventually formalised into an annual ritual in Bologna, Padua and other universities in Italy and subsequently other European centres (French, 1993). This took place in winter and continued over a period of three days. The order of the dissection was always the same — abdomen, thorax, cranium and limbs — although Mondino de Luzzi did not extend his own dissections to the limbs. The aim was to demonstrate anatomy, specifically a version of Galen’s account as developed by Mondino de Luzzi. The Professor of Anatomy did not undertake the dissection, but oversaw the procedure, demonstrating the findings with reference to Mondino’s Anathomia. The Professor of Anatomy provided the major intellectual force to the study of medicine during the Middle Ages and Renaissance.

The contribution of the Arab world to the advance of medicine in the second half of the first millennium was considerable. Although the Arabs did not perform human dissection, they translated Galen’s writings (in Greek) to Arabic. The original Greek sources were subsequently lost and the Latin versions of Galen used during the Middle Ages were based on translations from the Arabic. Despite the fact that Galen did not see a human dissection, his observations based on animal dissections and translated from Greek through Arabic to Latin were regarded as more reliable than the direct evidence obtained through human dissection. When there was a discrepancy, the fault lay with the corpse, not the writings of Galen! Perhaps man had degenerated since the time of the Graeco-Roman era!

THE RENAISSANCE

The Renaissance was characterised by an intense interest in the ancient world, and scholars rediscovered the original Greek sources of Galen’s work. For a period this gave Galen’s observations still greater authority, but it was the Brussels born anatomist Andreas Vesalius (1514–1564) who surmised correctly that Galen had not actually witnessed any human dissections. This realisation caused considerable controversy, because the Galenic writings had effectively been incorporated into the Catholic faith and Vesalius was therefore challenging the Church by believing the evidence of his own eyes. As Professor of Anatomy in Padua, he introduced the novel approach of conducting dissections personally and demonstrating the findings with the aid of an articulated skeleton and detailed life-sized engravings. Yet the underlying motivation of ritualised dissection remained as the exposition of the structural complexity of man’s hidden interior, in turn providing a glimpse into the mind of the Creator. This philosophical ideal was regarded as more important than any medical benefit and dissection was not conducted for the purposes of explaining disease. This was also the source of fascination for Leonardo da Vinci (1452–1519) who undertook human dissection and illustration as part of his insatiable pursuit of knowledge. Michelangelo (1475–1564) also dissected, largely to understand the sculptural contours of muscles and bones and so imbue his art with greater realism.

SEVENTEENTH CENTURY

It was not until the seventeenth century that human dissection began to be undertaken to determine the cause of death when the cause was known to be natural and not associated with suspicious circumstances. Pictorial records throughout this century depict the officially sanctioned anatomical dissection, a well-known example being The Anatomy Lesson by Rembrandt (1606–1669). These ritualised annual occasions were often conducted as a public spectacle fuelled by prurient interest at the prospect of seeing a corpse, not uncommonly that of a notorious criminal, gutted and dismembered as though this were a final and well-deserved punishment. This would have the effect of increasing the perceived sanctity of the body of non-transgressors and impeding the wider practice of autopsy as a means of comprehending the cause of death. Therefore, it is likely that autopsies undertaken to determine the cause of death were performed on poor or neglected individuals with no next of kin. However, the transition from annual anatomical dissection to autopsy for explaining death marks a major turning point in medical history.

In Rembrandt’s painting The Anatomy Lesson, Nicholas Tulp (1593–1674) displays the anatomy of the muscles of the left forearm of the body of an executed criminal (Schupbach, 1982). His left hand demonstrates the function of these muscles. Tulp was a religious man and his attitude in this painting is indicated in the following contemporary poem by Barlaeus (1645):

Evil men, who did harm when alive, do good after their deaths: Health seeks advantages from Death itself.

Dumb integuments teach. Cuts of flesh, though dead, for that very reason forbid us to die.

Here, while with artful hand he slits the pallid limbs, speaks to us the eloquence of learned Tulp:

‘Listener, know thyself! and while you proceed through the parts, believe that, even in the smallest, God lies hid’.

Tulp was also a physician, but as a demonstrator of anatomy he would have been well able to perform autopsies on his patients. This he did, leaving records of correlations between his diagnoses and diseased or morbid anatomy in Observationes Medicae (1641). The word ‘autopsy’ means seeing for oneself. Although Tulp was one of the first to see and illustrate abnormal anatomy that could offer an explanation for death, he was not unique in this regard in the seventeenth century. Other exponents included Theophile Bonet (1620–89) in France, Thomas Willis (1621–1675), the leading English anatomist of this period, and John Brown (1642–c.1700). John Brown was born in Norwich and practised surgery at St. Thomas’s Hospital in London. He had expertise in the management of tumours and was appointed as surgeon to Charles II and William III. In 1665, he communicated the first description of cirrhosis of the liver to the Royal Society of London. His detailed account was based upon the postmortem examination of a 25-year-old soldier who died of liver failure (Major, 1978c).

THE ENLIGHTENMENT

The two types of dissection, anatomical and pathological, continued side by side into the eighteenth century, but it was anatomical dissection that represented the central pillar of medical knowledge and took pride of place in medical school education. The concept of dissection being the final punishment of the poor and wicked was perpetuated in this century by the English painter William Hogarth (1697–1764) in a series of engravings entitled The Four Stages of Cruelty. In engraving 3 Tom Nero is caught murdering his mistress. After his death by hanging, his body is shown in engraving 4 being ceremoniously dissected at the Royal College of Physicians, the somewhat disinterested President taking the role of the traditional anatomist. Nero’s heart is greedily consumed by a dog (Burke & Caldwell, 1968).

There were still no professional pathologists in the eighteenth century. Autopsy to determine the cause of death when this was already known to be due to a natural cause remained as a rarely performed option for the interested physician. However the Professor of Anatomy in Padua, Giovanni Battista Morgagni (1682–1771) (working in the same dissection theatre as Vesalius two centuries before), kept meticulous records of his 640 postmortem examinations and towards the end of his career he published his life’s work, De sedibus et causis morborum (The Seat and Cause of Disease). He recognised the importance of altered anatomy as an indication of the cause of disease and carefully correlated what he observed with the patient’s life history. He sagely noted that: ‘Those who have dissected or inspected many bodies have at least learned to doubt, when others, who are ignorant of anatomy and do not take the trouble to attend it, are in no doubt at all’. Morgagni’s single scientific publication heralded the establishment of the autopsy as a powerful scientific tool.

Another factor which encouraged the development of pathology was the growth of an intellectual movement occurring throughout Europe founded on an ‘enlightenment’ that encompassed rationalism and anticlericalism. Jeremy Bentham (1748–1832), the English legal theorist and reformer and originator of the influential doctrine of utilitarianism, had the final word on the utility of the body as vehicle for teaching. He requested in his will that his skeletal remains be dressed and displayed in the university that he co-founded, University College, London. He made a more practical contribution, however, in the form of the Anatomy Act (1832), passed in the year of his death. Prior to this, the growth of private institutions for the teaching of medicine had resulted in a huge demand for cadavers which could not be met by the relatively small number of executed criminals. The shortfall was made good by the ‘resurrectionists’ or grave-robbers. The entire enterprise led to riots and the destruction of dissecting rooms by angry mobs (French, 1993). Bentham was opposed to capital punishment, but also perceived the importance of anatomical dissection. The Anatomy Act allowed bodies other than those of executed criminals to be dissected. This included body donation prior to death, which Bentham encouraged through his personal brand of body disposal. In practice the new generation of cadavers consisted of the unclaimed bodies of paupers, and dissection thus became a ‘punishment’ of the poor as well as the wicked.

NINETEENTH CENTURY

In the late eighteenth and early nineteenth centuries, Parisian physicians including Xavier Bichat (1771–1802) and Rene Laennec (1781–1826) (inventor of the stethoscope) conducted numerous autopsies on their own patients. Postmortem examination subsequently became more widely practised through the establishment of university chairs of pathology and institutes devoted to the study of pathology. Jean Cruveilhier (1791–1874) was appointed to the first professorship of pathological anatomy in Paris in 1836. He produced an elegantly illustrated atlas of pathological anatomy and is remembered for his accurate illustrations of gastric ulcers. It was not unusual for eminent individuals to be examined postmortem, an early example being Ludwig van Beethoven (1770–1827). In attendance at this occasion was the 23-year-old Karl Rokitansky (1804–1878). After graduating in medicine, Rokitansky specialised in pathology at the Vienna Hospital, becoming Professor of Pathology at the University of Vienna in 1844. Rokitansky devoted all his time to autopsy examinations, claiming to have performed 30,000 by 1866. By this time pathology, spawned from the discipline of anatomy, had replaced the older discipline as the cornerstone of academic medicine. Postmortem examination spread from Europe to America, mainly through the emigration of talented physicians from Germany. The surgeon and reformer of medical education Adam Hammer (1818–1878) settled in St. Louis, Missouri in 1848. In 1876 he commented: ‘Obtaining an autopsy in America is attended by great difficulties. How often I have purchased this permission by giving up my fee for professional services! Indeed in certain cases I have had to pay money out of my own pocket to succeed. Before this universal medium even the most subtle misgivings, even the religious ones, soften’ (Major, 1978a).

Despite his eminence and unrivalled knowledge of disordered anatomy, Rokitansky still believed that the fundamental cause of disease lay in the imbalance of a humoral or fluid-based factor. It would take a still greater intellect to challenge this doctrine handed down from the Greeks through the writings of Galen. But something new and important was happening. The light microscope, used systematically for the first time by the Netherlandish naturalist Antony van Leeuwenhoek (1632–1723), had been greatly refined and was being applied extensively by the German pathologist Rudolf Virchow (1821–1902). Histopathology (meaning the microscopic examination of diseased tissues) was to evolve from microscopic anatomy via the influence of Virchow, just as the postmortem examination had evolved from anatomical dissection two centuries before.

Virchow was a staunch campaigner for social justice and his outspoken criticisms of the Prussian government led to his dismissal from his post in Berlin. He moved to Würzburg where as professor of pathology and dir...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Acknowledgements
• Introduction
• Part I Anatomical Pathology: An Evolving and Integrating Discipline
• Part II Injury, Inflammation And Immunity
• Part III Blood, Tubes, Fluids and Flow
• Part IV Neoplasia
• Part V Messengers, Metabolism, Multisystem and Mechanical Disease
• Glossary
• Index