The Papanicolaou test (also called Pap smear, Pap test, cervical smear, or smear test) is a screening test used in to detect pre-cancerous and cancerous processes in the endocervical canal (transformation zone) of the female reproductive system.
Changes can be treated, thus preventing cervical cancer. The test was invented by and named after the prominent Greek doctor Georgios Papanikolaou. An anal Pap smear is an adaptation of the procedure to screen and detect anal cancers.
In taking a Pap smear, a speculum is used to open the vaginal canal and allow the collection of cells from the outer opening of the cervix of the uterus and the endocervix. The cells are examined under a microscope to look for abnormalities.
The test aims to detect potentially pre-cancerous changes (called cervical intraepithelial neoplasia (CIN) or cervical dysplasia), which are usually caused by sexually transmitted human papillomaviruses. The test remains an effective, widely used method for early detection of pre-cancer and cervical cancer. The test may also detect infections and abnormalities in the endocervix and endometrium.