Cytology is a common method for determining a diagnosis in the medical world. Cytology tests use small amounts of bodily tissue or fluid in order to examine certain types of cells. Healthcare providers can use cytology tests for almost all areas of your body.
Cytology (also known as cytopathology) involves examining cells from bodily tissues or fluids to determine a diagnosis. A certain kind of physician, called a pathologist, will look at the cells in the tissue sample under a microscope and look for characteristics or abnormalities in the cells. Since cytology only examines cells, which are so tiny, pathologists only need a very small sample of tissue to do a cytology test.
Healthcare providers use cytology in many different areas of medicine, but cytology tests are most commonly used to screen for or diagnose cancer.
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There are two main kinds, or branches, of cytology: exfoliative cytology and intervention cytology.
Healthcare providers can use cytology tests for almost all areas of your body. Some common types of cytology tests include:
Exfoliative cytology is a branch of cytology in which the cells that a pathologist examines are either “shed” by your body naturally or are manually scraped or brushed (exfoliated) from the surface of your tissue.
Examples of exfoliative cytology that involve manual tissue brushing or scraping include:
Examples of exfoliative cytology that involve collecting tissues or fluids that your body naturally sheds include:
Intervention cytology is a branch of cytology in which your healthcare provider has to “intervene” with your body to get a sample of cells to test, meaning they have to pierce your skin in some way to get a sample of cells.
The most common type of intervention cytology is fine-needle aspiration (FNA). A healthcare provider will inject a thin needle into the area that they need to sample and draw out fluid. A pathologist then examines the cells in the fluid under a microscope.
Some areas of your body that a healthcare provider may perform a fine-needle aspiration include:
Healthcare providers and pathologists most commonly use cytology to diagnose or screen for cancer.
A healthcare provider only uses a diagnostic test for a person if they have signs or symptoms that suggest they might have a certain disease or infection. A diagnostic test, such as a cytology test, determines if abnormal cells are present. If so, the test accurately classifies the disease.
A healthcare provider uses screening tests to see if a person could have a certain disease, such as cancer, even before they experience symptoms. A popular type of cytology screening test is a Pap smear.
Other uses for cytology tests include:
Depending on the type of cytology test, many types of healthcare providers could collect the sample of cells. For example, a gynecologist may take a sample from your cervix for a Pap smear cytology test. The healthcare provider then sends the sample to a laboratory for testing. A pathologist or cytopathologist looks at the cells from the tissue sample under a microscope and determines a diagnosis, if applicable.
Each cytology test is slightly different depending on what kind of cells are being tested and if the sample is tissue or fluid. In general, there are four steps to a cytology test including:
Here’s an explanation of the steps of a cytology test.
Collecting the sample cells
Your healthcare provider collects the sample of cells from your body that they need a pathologist to examine. Some of the ways a provider can collect cytology test samples include:
Processing the sample cells
For some types of cytology tests that involve tissue samples, the healthcare provider who took the sample smears or spreads it on glass microscope slides. These slides are known as smears. They then send the smears to a pathology laboratory.
If the cytology test involves bodily fluid, the healthcare provider most likely won’t be able to use smears since the sample is too diluted (there are only a few cells in the fluid). They’ll most likely send the sample to a pathology lab in a small container.
Once a cytology sample arrives at the laboratory, a pathologist or lab technician dips the smears in certain stains (colored dyes) depending on what kind of sample it is. The stains help make the cells easier to see and examine under a microscope.
If the cytology sample is a fluid, a pathologist or lab technician may use a machine called a centrifuge to separate the cells they want to examine from the fluid. A centrifuge separates certain cells from fluid by spinning the sample very quickly. The pathologist then puts the cells on smears and may stain them.
Examining the sample cells
After a pathologist or lab technician processes and stains the cytology samples, they examine the cells under a microscope, looking for abnormal cells. If they find abnormal cells, they mark them on the slides with a special pen. A pathologist then makes a diagnosis based on the cells and puts together a report.
Sharing the results
After they put together a report, the pathologist will send it to your healthcare provider. Your provider will go over the results with you and determine the next steps.
Most cytology tests are simple and painless, so you don’t have to do anything special to prepare for them. Your healthcare provider will explain the process of your specific cytology test and will let you know if you need to do anything to prepare.
The healthcare provider who performed your cytology test will send the tissue sample cells to a laboratory where a cytologist or pathologist will examine the cells under a microscope, looking for abnormal cells or certain characteristics. The pathologist will then send a report of the findings to your healthcare provider, who will share the results with you.
Complications from cytology tests are very rare and if they happen, they’re often mild. Like many types of medical tests, a cytology test can give a false negative or false positive result. Additionally, in some cases, tissue biopsies can be more accurate than cytology tests.
Cytology tests have many benefits due to the small amount of tissue or fluid sample that is needed for the test. Compared to a tissue biopsy, which healthcare providers also use to determine a diagnosis, a cytology test:
The type of results you get from a cytology test depends on what type of test it is and what part of your body was sampled.
A pathologist’s report for a cytology test may include:
The time it takes to get the results of your cytology test depends on certain factors like what kind of tissue cells were examined. Some routine cytology screenings could take as little as 1 to 2 days to get your results while other tests could take 1 to 2 weeks. Factors that affect how long it takes to get cytology test results include:
Cytology (cytopathology) is a branch, or subspecialty, of pathology. In medicine, pathology deals with the laboratory examination of cells in samples of body tissue or fluids for diagnostic purposes.
Cytology and histology are different branches of pathology. Cytology generally involves looking at individual cells or clusters of cells. Histology involves examining an entire section of tissue, which contains many types of cells.
The goal of both cytology tests and biopsies is to determine a diagnosis, but they have some differences.
By definition, cytology is the examination of individual cells or clusters of cells, so pathologists only need a very small sample to look at under a microscope for cytology tests. Because of this, cytology tests are usually painless.
Biopsies usually involve larger pieces of tissue than a cytology test needs, and a pathologist may examine several types of cells in a tissue sample taken from a biopsy. Biopsy procedures are also generally more invasive than cytology tests and may require local or general anesthesia.
A note from Cleveland Clinic
Cytology tests are a very common and often painless way to determine a diagnosis and screen for cancers. While it can be stressful to wait for the results of a diagnostic test, know that your healthcare team is there to support you no matter what the results are. Don’t be afraid to ask your healthcare provider questions about your test or results.
Last reviewed by a Cleveland Clinic medical professional on 08/17/2021.
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