Cytology (Cytopathology)

What is cytology (cytopathology)?

Cytology (also known as cytopathology) is a way to diagnose or screen for diseases by looking at cells under a microscope. A pathologist looks for changes in cells in a small sample of body fluid or tissue. These changes can indicate cancer or precancerous conditions. They can also look for infections, like bacteria, parasites, fungi and viruses.

Is cytology part of pathology?

Cytology is one of three main sections in anatomic pathology. It’s also called a branch, or subspecialty, of anatomic pathology. Anatomic pathology is the diagnostic study of diseases in tissues and various organ sites and their causes. Pathologists examine tissues and fluids from your body to diagnose disease.

Why would a doctor order a cytology test?

A healthcare provider might order a cytology test to:

• Screen for and diagnose cancer
• Diagnose infectious diseases
• Diagnose inflammatory conditions (like sarcoidosis)

Types of cytology

There are three types of cytology, based on the way your provider gets the sample: exfoliative, abrasive and intervention (or fine needle aspiration cytology).

Exfoliative cytology

When a pathologist examines cells that are naturally shed by your body, it’s called exfoliative cytology. These cells are found in body fluids or secretions. Samples your provider might use for exfoliative cytology include:

• Spit
• Sputum (mucus coughed up from your lungs)
• Pee (urine cytology)
• Discharge from places like your eye, vagina or nipple
• Cerebrospinal fluid (for instance, from a lumbar puncture)
• Fluid from around your heart, lungs or abdominal organs (pericardial, pleural or peritoneal effusions)

Abrasive cytology

When a provider uses a procedure to dislodge and remove cells to be examined (like brushing or scraping), it’s called abrasive cytology. They can also use washing or lavage techniques, which means they use a solution to loosen cells and then collect them. Examples of abrasive cytology include:

• Pap smear: A provider gets samples from your cervix using a swab. This is one of the most well-known types of cytology.
• Bronchioalveolar lavage, washings or brushings: A provider can get samples from your airways or lungs during a bronchoscopy.
• Lavage, washings or brushings from your digestive tract: Cytology of your digestive tract is most commonly done on samples from your esophagus, stomach or small intestines taken during an endoscopy.
• Skin scrapings: A provider can scrape a sample from a rash or sore on your skin to diagnose infectious diseases.
• Mucous membrane scraping or swabbing: This includes swabbing your nose, throat or the inside of your cheek.

Intervention/aspiration cytology

Intervention cytology is when a provider collects the fluid sample using a small needle to pierce your skin. This is also called fine-needle aspiration (FNA) or aspiration cytology.

Providers use interventional cytology on lumps or masses they can feel from the outside, for instance:

• Enlarged lymph nodes
• Thyroid nodules
• Salivary masses
• Head and neck masses
• Breast lumps

How does a cytology test work?

Cytology allows a pathologist to see different parts of your cells. Your healthcare provider performs a Pap smear, endoscopy, fine-needle aspiration or other procedure to get a sample. They send the sample to a lab.

A cytopreparatory technologist stains the sample with colored dyes so the cytologist and/or the pathologist can see cells and their parts. They look for changes or abnormalities in the numbers of cells that can indicate diseases.

How do I prepare for a cytology test?

Most of the time, you don’t need to do anything specific to prepare for a cytology test. But every test is a little different, so ask your provider if there’s anything you need to do before your test.

What happens during a cytology test?

Each cytology test is slightly different depending on the kind of cells providers are testing and whether the sample is tissue or fluid. In general, the steps of a cytology test include:

1. Collecting the sample: Your healthcare provider collects the sample of cells from your body that they need a pathologist to examine. They might brush or scrape a tissue sample, collect discharge or body fluids (like pee) or perform an FNA.
2. Sending the sample to a lab: Your provider sends the sample to be tested on glass slides (smears) or in a small container.
3. Preparing the sample: Steps in preparing might include separating the cells from the body fluid, mounting them on a slide, preserving (fixing) the sample, dipping the sample in stains and other preparations.
4. Examining the sample: A cytologist screens the slides by looking at the cells under a microscope for changes and abnormalities. They send them to the pathologist for review. They might also look for germs (pathogens) like bacteria or parasites.
5. Creating a report: The pathologist reviews the screened slides and will write a final report that shares their findings and diagnosis.

What should I expect after having a cytology test?

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.

What are the risks of cytology tests?

Complications from cytology tests are very rare. Some risks include infection and false-negative or false-positive results.

What are the advantages of cytology tests?

Compared to a tissue biopsy — another type of test that examines cells for diagnosis — a cytology test:

• Only requires a small amount of tissue or fluid
• Is less invasive
• Causes less discomfort and pain
• Is less likely to cause complications

What type of results do you get from a cytology test?

The type of results you get from a cytology test depends on what the test was for (for instance, screening or diagnosis) and what part of your body the sample was from.

Possible results include:

• Normal or negative result: This can mean that no abnormal or cancerous cells were found, or that no infection was found.
• Undetermined, unsatisfactory or inadequate result: This might mean that the sample didn’t have enough cells or the pathologist couldn’t get a good enough look at the cells.
• Abnormal or positive result: This can mean your cells look different than normal cells under a microscope, or that the pathologist found an infection. This doesn’t necessarily mean you have cancer. You might see words like dysplasia, hyperplasia, metaplasia, hypertrophy or atrophy.

You may also see:

• Grading: Pathologists give cancerous and precancerous cells a grade to indicate how similar they look compared to normal cells or tissues.
• Recommendations: They might recommend further testing, like a biopsy.

How long does it take to get the results of a cytology test?

The time it takes to get the results of your cytology test depends on many factors, like what kind of cells the provider examined. Some routine cytology screenings could take as little as a day or two to get your results, while other tests could take one to two weeks.

If the results are abnormal, what are the next steps?

Next steps depend on what you were being tested for and what the abnormal results mean. Your provider will let you know if you need additional testing or if they recommend treatment.

When should I call my doctor?

Talk to your healthcare provider if you have any questions about the procedure to collect the cytology sample or about the test results.

What’s the difference between cytology and a biopsy?

The goal of both cytology tests and biopsies is to diagnose or rule out diseases, but they have some differences. 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.

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.