Journal of Cellular & Molecular Pathology

The test is usually used to look for cancers and precancerous changes. It may also be used to look for viral infections in cells. The test differs from a biopsy because only cells are examined, not pieces of tissue.

The Pap smear is a common cytologic evaluation that looks at cells from the cervix. Some other examples include:

• Cytology exam of fluid from the membrane around the lungs (pleural fluid).
• Cytology exam of urine.
• Cytology exam of saliva mixed with mucus and other matter that is coughed up (sputum).