Gynecological cytology is the microscopic examination of cells collected from the female reproductive tract, primarily the cervix, to detect cellular changes that may indicate the presence of disease. This procedure serves as a powerful tool in preventative healthcare, most notably for screening against cervical cancer. The goal is to identify precancerous abnormalities at a very early stage, allowing for timely intervention and preventing the progression to invasive cancer. This routine test contributes significantly to long-term reproductive health.
The Role of Cervical Screening
The primary application of gynecological cytology is the Papanicolaou (Pap) test, which is a highly effective method for cervical cancer screening. This screening is performed to identify precancerous cell changes, known as dysplasia, that often develop slowly over time. Most cervical cancers are caused by persistent infection with high-risk types of the Human Papillomavirus (HPV). The Pap test looks for the cellular evidence of this infection and its potential consequences. Finding these abnormal cells early, before they become cancerous, increases the chance of successful treatment.
Patient preparation before the test is important. Patients are advised to avoid douching, using vaginal medicines, creams, or spermicidal foams for at least 48 hours before the appointment. Refraining from sexual intercourse for 24 to 48 hours beforehand is also recommended. The test should ideally be scheduled outside of the menstrual period, as excessive blood can make the sample difficult for the lab to interpret.
During the collection procedure, the patient lies on an exam table with their feet in supports called stirrups. A healthcare provider gently inserts a speculum into the vagina to hold the walls open, allowing the cervix to be seen. A small brush or spatula is then used to gently collect a sample of cells from the surface of the cervix and the endocervical canal. This gentle scraping may cause a feeling of pressure or mild cramping, but the collection itself is very quick, usually taking only a few minutes.
The Cytology Laboratory Process
Once the cell sample is collected, it is sent to the cytology laboratory. The way the sample is processed depends on the collection method used by the clinician, which is typically either a conventional smear or the more common liquid-based cytology (LBC). With LBC, the brush or sampling device is rinsed into a vial of preservative fluid instead of being smeared directly onto a glass slide. This technique helps to preserve the cells and removes obscuring factors like blood or mucus, which often results in a higher-quality, more readable specimen.
In the laboratory, automated instruments prepare the LBC sample by creating a thin, uniform layer of cells on a slide for microscopic viewing. The slides are then stained using a method like the Papanicolaou stain, which colors the different cellular components to make them easily visible. A trained cytotechnologist or pathologist examines the slides under a microscope, looking for any cells with abnormal morphology. They focus on characteristics such as the cell’s shape, the size of the nucleus, and the ratio of the nucleus to the cell’s cytoplasm, which can indicate precancerous changes.
The findings are classified using a standardized reporting system, most commonly the Bethesda System. This system provides uniform terminology for describing the specimen quality and the presence and severity of any cellular abnormalities. The lab report will ultimately use this classification to communicate the final interpretation of the cellular findings back to the healthcare provider.
Decoding Your Results and Follow Up
The classification system used in the final report dictates the necessary follow-up care. A result of “Negative for Intraepithelial Lesion or Malignancy” is considered normal, indicating no cellular abnormalities were found. When abnormalities are detected, the results fall into specific categories that describe the degree of cellular change.
“Atypical Squamous Cells of Undetermined Significance” (ASCUS) is the most common abnormal finding. For an ASCUS result, the next step is often reflex Human Papillomavirus (HPV) testing on the same sample, or a repeat Pap test in six to twelve months. If high-risk HPV is found, or if the abnormality persists, the patient is usually referred for a colposcopy.
A “Low-Grade Squamous Intraepithelial Lesion” (LSIL) suggests a mild abnormality. Management for LSIL depends on the patient’s age and HPV status, but it frequently involves monitoring with repeat testing after a year. However, if the LSIL persists over two years or is found in older patients, a closer look with colposcopy may be recommended.
A “High-Grade Squamous Intraepithelial Lesion” (HSIL) is a more significant finding, indicating moderately to severely abnormal cells that carry a higher risk of developing into cancer. In this case, immediate referral for a colposcopy is the standard of care to allow the provider to closely examine the cervix and take a tissue sample (biopsy). Another classification is “Atypical Squamous Cells, Cannot Exclude HSIL” (ASC-H), which also requires immediate colposcopy due to the possibility of a high-grade lesion.