Diagnostic cytopathology

This chapter deals with diagnostic cytopathology, which is the diagnosis of disease at the cellular level and involves the preservation, staining, and microscopic examination of cells that have been extracted from the body. It looks at a variety of human diseases that can be diagnosed with diagnostic cytopathology, such as infections, crystal deposition diseases, and benign tumours. It also outlines the two modalities in which diagnostic cytopathology may be used: as a screening test for the early detection of precancerous lesions in asymptomatic individuals, and as a diagnostic test for the identification of cancer cells in symptomatic patients. The chapter illustrates that the microscopic interpretation of cells taken from the human body is often not straightforward. It explains that inflammatory disease, cell degeneration, regenerative process, and a wide array of benign conditions represent pitfalls which can entrap the unwary or inexperienced cytologist.