Article: Pap smear

A pap smear (also called Pap test and smear test) is a medical screening test for detecting pre-cancerous changes (termed dyskaryosis derived from Greek, meaning 'bad-nut') and thus aims to prevent the development of cancer and other abnormalities in the female genital tract by sampling cells from the cervix with an Aylesbury spatula or (more frequently with the advent of liquid-based cytology) a plastic-fronded broom. The cells are placed on a glass slide and checked for abnormalities in the laboratory. The test is simple and effective.

Since the mid-1990s, techniques based around placing the sample into a vial containing a liquid medium which preserves the cells have been increasingly used. The media are primarily ethanol based. Two of the types are Sure-Path (Medical Solutions) and Thin-Prep (Cytyc Corp). Once placed into the vial, it is usually sent to the laboratory. There, the sample is processed at the laboratory and placed onto a glass slide there.

The sample is stained using the Papanicolaou technique, in which tinctorial dyes and acids are selectively retained by cells. The aim of the staining technique is to aid identification of the abnormal or dyskaryotic cells by them staining differently to the benign cells.

The sample is then screened by a scientist or laboratory technician using a microscope. The terminology for whom screens the sample varies according the country - in the UK the personnel are known as Cytoscreeners, Biomedical Scientists (BMS), Advanced Practitioners and Pathologists. The latter two take responsibility for reporting the abnormal sample which may require further investigation.

About 5% to 7% of pap smears produce abnormal results, such as dysplasia, a possibly pre-cancerous condition. Many of these abnormalities are not due to cervical cancer, but they are an indicator that increased vigilance is needed.

Depending on the guidelines of the screening program in a given country, it is recommended that all sexually active women have an annual or biannual smear test to detect any cancer in its early stages. If results are abnormal, and depending on the nature of the abnormality, the test may need to be repeated in three to twelve months. If the abnormality requires closer scrutiny, the patient may be referred for a colposcopy.

In the United States, physicians who fail to diagnose cervical cancer from a pap smear have been convicted of negligent homicide. In 1988 and 1989, Karen Smith had received pap smears which were argued to have "unequivocally" shown that she had cancer; yet the lab had not made the diagnosis. She died on March 8, 1995. Later, a physician and a laboratory technician were convicted of negligent homicide.

History

The test was invented by Dr. Georgios Papanikolaou (1883-1962). He was a Greek from the island of Evia (specifically the Karystia region) who later emigrated to the United States of America, and the father of cytopathology. "Pap" is an abbreviation for Papanicolaou.

Based on his thirty years of work at New York Hospital and the Weill Medical College of Cornell University, Papanikolaou published a large series of cases in Diagnosis of uterine cancer by the vaginal smear (Papanicolaou & Traut, 1943). The sampling technique has hardly changed ever since.

Popular culture

A villain in the Naked Gun films is called Papschmir, an obvious reference to this kind of test.

Georg Ruthenberg, guitarist for L.A. punk rock band the Germs, renamed himself "Pat Smear" as a reference to the procedure.