Pathology is the study and diagnosis of disease through examination of organs, tissues, cells and bodily fluids. The term includes both the medical specialty which uses tissues and body fluids to obtain clinically useful information, as well as the related scientific study of disease processes. The history of Pathology goes back to the Middle East during the Islamic Golden Age and Western Europe during the Italian Renaissance. Most early pathologists were also physicians or surgeons. Pathology has become progessively more specialized and most pathologists today do not practice in other areas of medicine.
The concept of studying disease through the dissection and examination of diseased bodies, organs, and tissues may seem obvious today, but there are few if any recorded examples of true autopsies performed prior to the second millennium. The pathology of contagion was understood by Muslim physicians around 1000 AD. The most famous early gross pathologist was Giovanni Morgagni (1682-1771). His magnum opus was published in 1761 and describes the findings of over 600 partial and complete autopsies, organized anatomically and methodically correlated with symptoms exhibited by the patients prior to their deaths. Although the study of normal anatomy was already well advanced at that time, by the late 1800s, an large body of literature had been produced on the gross anatomical findings characteristic of known diseases. The extent of gross pathology research in this period can be seen in the work of the Viennese pathologist Carl Rokitansky (1804-1878), who is said to have performed 20,000 autopsies, and supervised an additional 60,000, in his lifetime.
Rudolf Virchow (1821-1902) is generally recognized as the father of microscopic pathology. While the compound microscope had been invented approximately 150 years before, Virchow was one of the first prominent physicians to emphasize the study of manifestations of disease which were visible only at the cellular level. His student, Julius Cohnheim (1839-1884) combined histology techniques with experimental manipulations to study inflammation, making him one of the earliest experimental pathologists. Cohnheim also pioneered the use of the frozen section procedure and a version of this technique is widely employed by modern pathologists to make diagnoses and provide other clinical information during surgical procedures.