Page 25 - Textbook of Pathology, 6th Edition

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Techniques for
Chapter 2
Chapter 2
the Study of Pathology CHAPTER 2

For learning contemporary pathology effectively, it is essential iii) study of demography and epidemiology of diseases;
that the student is familiar with the various laboratory and
methods, techniques and tools employed for the study of iv) affords education to students and staff of pathology.
pathology. This chapter is devoted to the basic aspects of Declining autopsy rate throughout world in the recent times
various such methods as are available in a modern pathology is owing to the following reasons:
laboratory—ranging from the basic microscopy to the most 1. Higher diagnostic confidence made possible by advances
recent methods. in imaging techniques e.g. CT, MRI, angiography etc.
2. Physician’s fear of legal liability on being wrong.
AUTOPSY PATHOLOGY Continued support for advocating autopsy by caring
physicians as well as by discernible pathologists in tertiary-
Professor William Boyd in his unimitable style wrote
‘Pathology had its beginning on the autopsy table’. The care hospitals is essential for improved patientcare and Techniques for the Study of Pathology
significance of study of autopsy in pathology is summed up progress in medical science.
in Latin inscription in an autopsy room translated in English
as “The place where death delights to serve the living’. As SURGICAL PATHOLOGY
stated in the previous chapter, G.B. Morgagni in Italy (1682-
1771) and T.H.A. Laennec (1781-1826) in France started HISTORICAL PERSPECTIVE
collecting the case records of hospital cases and began
correlation of clinical features with the lesions observed at The term surgical pathology is currently applied synony-
autopsy and thus marked the beginning of clinicopathologic mously with histopathology, morbid anatomy, anatomic
correlation (CPC). CPC continues to be the most important pathology and cellular pathology. Surgical pathology is the
form of clinical teaching activity in medical institutions classic and time-tested method of tissue diagnosis made on
worldwide. gross and microscopic study of tissues.
There is still no substitute for a careful postmortem As discussed already, surgical pathology made a
examination which enlightens the clinician about the patho- beginning from pathologic study of tissues made available at
genesis of disease, reveals hazardous effects of therapy autopsy. Surgeons of old times relied solely on operative or
administered, and settles the discrepancies finally between gross findings and, thereafter, discarded the excised tissues,
antemortem and postmortem diagnosis. without affording an opportunity to the pathologist to make
Traditionally, there are two methods for carrying out microscopic diagnosis. However, with technology
autopsy, either of which may be followed: development and advances made in the dye industry in the
1. Block extraction of abdominal and thoracic organs. initial years of 20th Century, the speciality of diagnostic
2. In situ organ-by-organ dissection. surgical pathology by biopsy developed.
In conditions where multiple organs are expected to be In the beginning, this task was assigned to a surgeon
involved, complete autopsy should be performed. But if a faculty member in the surgery departments who was
particular organ-specific disease is suspected, a mini-autopsy appropriately called ‘surgical pathologist’. Currently, the field
or limited autopsy may be sufficient. of surgical pathology has expanded so much that several
The study of autopsy throws new light on the knowledge subspecialities have developed e.g. nephropathology,
and skills of both physician as well as pathologist. The main neuropathology, haematopathology, dermatopathology,
purposes of autopsy are as under: gynaecologic pathology cytopathology, paediatric pathology,
1. Quality assurance of patientcare by: and so on.
i) confirming the cause of death;
ii) establishing the final diagnosis; and SCOPE AND LIMITATIONS OF SURGICAL PATHOLOGY
iii) study of therapeutic response to treatment.
2. Education of the entire team involved in patientcare by: Surgical pathology services in any large hospital depend
i) making autopsy diagnosis of conditions which are often largely on inputs from surgeons and physicians familiar with
missed clinically e.g. pneumonia, pulmonary the scope and limitations inherent in the speciality. Thus it is
embolism, acute pancreatitis, carcinoma prostate; vital that clinician and pathologist communicate freely—
ii) discovery of newer diseases made at autopsy e.g. formally as well as informally, through surgical pathology
Reye’s syndrome, Legionnaire’s disease, severe acute request forms, verbally, and at different fora such as tissue
respiratory syndrome (SARS); committees and interdepartmental conferences.