Sputum Cytology

Test Overview

Sputum cytology examines a sample of sputum (mucus) under a microscope to determine whether abnormal cells are present. Sputum is not the same as saliva. Sputum is produced in the lungs and in the airways leading to the lungs. Sputum has some normal lung cells in it.

Sputum cytology may be done to help detect certain noncancerous lung conditions. It may also be done when lung cancer is suspected.

A sputum sample may be collected:

• By a person coughing up mucus.
• By breathing in a saltwater (saline) mist and then coughing.
• During bronchoscopy, which uses a bronchoscope to look at the throat and airway.

Why It Is Done

Sputum cytology is done to find:

• Lung cancer. But sputum cytology is not used as a screening test for people at risk for developing lung cancer, such as smokers.
• Noncancerous lung conditions, such as pneumonia or inflammatory diseases, tuberculosis, or the buildup of asbestos fibers in the lungs (asbestosis).

How To Prepare

Home or office sample

No special preparation is needed if the sputum sample is to be collected at home or in your doctor's office.

Bronchoscopy sample

Your doctor will tell you how soon before the procedure to stop eating and drinking. Follow the instructions exactly about when to stop eating and drinking, or your surgery may be canceled. If your doctor has instructed you to take your medicines on the day of surgery, please do so using only a sip of water.

Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.

How It Is Done

Home or office sample

Three sputum samples are usually collected over 3 days. Your doctor will give you a container to collect the sputum. This container may have a small amount of liquid (called fixative) in it. The fixative helps preserve the sample. Do not drink this liquid.

For best results, collect the sample soon after you wake up, before you eat or drink anything. Follow these steps:

• If you wear dentures, remove them before collecting the sample.
• Rinse your mouth with water.
• Take about four deep breaths followed by a few short coughs, then inhale deeply and cough forcefully into the container. Sputum is not the same as saliva, so make sure to get a sample of mucus from deep in your airway. Collecting the sample in the morning, when you first wake up, is generally best.
• If you have trouble obtaining a good sample, try taking a hot shower first to help loosen the mucus in your airway.

Carefully follow your doctor's instructions about where to deliver the sample. You may be instructed to take the sample to the doctor's office or to a laboratory. Deliver the sample soon after you obtain it. You may be instructed to refrigerate the sample if you are not able to deliver it immediately.

Bronchoscopy sample

During bronchoscopy, a thin, lighted instrument (bronchoscope) is inserted through the nose or mouth into the throat and then into the airways leading to the lungs.

How It Feels

Home or office sample

If you have discomfort when taking a deep breath or coughing, getting a sputum sample may be uncomfortable.

Bronchoscopy sample

You may be able to feel pressure in your airway as the bronchoscope is moved from place to place. You may gag or cough. If you have general anesthesia, you will feel nothing during the procedure.

Risks

Home or office sample

There are no known risks from having this test.

Bronchoscopy sample

Bronchoscopy is generally a safe procedure. Although complications are rare, you should discuss the risks in your particular case with your doctor. Complications that may occur include:

• Spasms of the bronchial tubes. These can impair breathing.
• Irregular heart rhythms (arrhythmias).
• Infection, such as pneumonia. These usually can be treated with antibiotics.

Results

It may take several days to receive results from a sputum cytology.