Role of the Pathologist

The pathologist is a specialist trained to examine tissues and cells for the presence of disease. There are major subdivisions of pathology significant to determining the presence and nature of cancer. In cytopathology, a cytologist studies the presence and effects of diseases within cells, while in histopathology, a histologist specializes in the study of tissues.

For tests that require the analysis of cells, as with the Pap test, the cytologist stains the slide containing the sample with a dye. The cytologist can then examine the cells for changes and grade them in terms of degree of change.

For the examination of tissues, as with a biopsy, the histologist follows a series of steps for a complete analysis; initially, he or she evaluates the characteristics of the tissue grossly (with the naked eye). The tissue is then sliced with a sharp knife so that it can be further examined. At this point the histologist may make a preliminary, or gross, diagnosis. Often, a histologist will use a microscope in order to view the sample more clearly. The remaining tissue undergoes a series of steps that allow for a more detailed and definitive analysis. This process results in high-quality slides called permanent sections. The histologist uses them to make the final diagnosis, which usually takes three to five days.