What is liquid-based cytology?
Dec 29, 2020
Source: Cainiu Health
Dr. Wang Huiming
Introduction
What is Liquid-Based Cytology (LBC)?
Liquid-based cytology (LBC), also known as ThinPrep Cytologic Test (TCT), is a primary screening method used to detect cervical cancer and precancerous lesions. This test should be performed after menstruation has completely ended—i.e., when there is no menstrual bleeding—and under the following conditions: abstain from sexual intercourse for at least 3 days prior to the test; avoid vaginal douching for 24 hours before the test; and refrain from using any vaginal medications for 24 hours before the test. Patients may then visit a hospital to undergo this examination.
Liquid-based cytology (LBC) is a subset of exfoliative cytology. It involves placing traditionally difficult-to-process exfoliative cytology specimens into a special liquid medium to remove interfering components—such as blood and mucus—that hinder accurate diagnosis, thereby improving diagnostic sensitivity and accuracy. This liquid medium, known as cytological preservative solution, serves multiple functions: preserving cellular morphology, dissolving mucus, and lysing red blood cells. So, what exactly is liquid-based cytology? Below is a detailed explanation.
What Is Liquid-Based Cytology?
Liquid-based cytology—commonly referred to as ThinPrep Cytologic Test (TCT)—is primarily used as an initial screening method for cervical cancer and its precancerous lesions. The test should be performed after menstruation has completely ended, with no vaginal bleeding present. To ensure optimal specimen quality, patients must abstain from sexual intercourse for at least three days prior to the test, avoid vaginal douching for 24 hours, and refrain from applying any vaginal medications for 24 hours before the procedure. During the examination, a gynecologist performs a pelvic exam using a speculum to visualize the cervix and collects cells from the transformation zone—the junction between squamous and columnar epithelial cells—at the cervical os and within the endocervical canal. These cells are then placed into a standardized preservative vial for pathological analysis. Alternatively, a specialized cytobrush may be used to gently rotate around the external cervical os and inside the cervical canal to collect exfoliated cells, which are subsequently sent to the pathology laboratory for evaluation. This method is highly effective in detecting precancerous cervical lesions.
Additional Information: Precautions Before Cervical Liquid-Based Cytology
1. Abstain from sexual intercourse for at least 24 hours prior to the test. Semen residue on the slide may obscure abnormal cells, increasing the risk of false-negative results.
2. Avoid vaginal douching for 24–48 hours before the test. If undergoing treatment for vaginitis—including use of vaginal suppositories—discontinue such medications 24–48 hours prior to the procedure. Additional vaginal examinations should also be avoided during this period.
3. Active cervical inflammation should be adequately treated and resolved before performing liquid-based cytology.
4. Generally, liquid-based cytology is not recommended during menstruation.
The above provides an overview of liquid-based cytology. We hope this information is helpful to you.
