In this method, cells are collected after they have been either spontaneously shed by the body ("spontaneous exfoliation ''), or manually scraped / brushed off of a surface in the body ("mechanical exfoliation ''). An example of spontaneous exfoliation is when cells of the pleural cavity or peritoneal cavity are shed into the pleural or peritoneal fluid. This fluid can be collected via various methods for examination. Examples of mechanical exfoliation include Pap smears, where cells are scraped from the cervix with a cervical spatula, or bronchial brushings, where a bronchoscope is inserted into the trachea and used to evaluate a visible lesion by brushing cells from its surface and subjecting them to cytopathologic analysis. Liquid - based cytology collects the samples in the same way but places them in liquid that is then treated to allow for improved results.
in exfoliative cytology the cells for examination are obtained by
spontaneously shed by the body or manually scraped / brushed off of a surface in the body