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Sputum Cytology


Sputum cytology examines a sample of sputum (mucus) under a microscope to determine whether abnormal cells are present. It may take several days to receive results from a sputum cytology.

Sputum cytology

Normal lung cells are present in the sputum sample.


Abnormal cells are present in the sputum sample. Abnormal cells may mean lung conditions such as pneumonia, inflammation, the buildup of asbestos fibers in the lungs (asbestosis), or lung cancer.

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include a sample that is too small; is dried out; contains only saliva; or is from nasal secretions, not your airway.

What To Think About

  • There is a chance of false-negative test results with sputum cytology. This means that the test shows a lung condition is not present when it actually is present. Follow-up testing may need to be done if your symptoms continue.
  • A sputum culture is a test to find and identify bacteria or fungi that are infecting the lungs or breathing passages. It is also done to identify the best antibiotic to treat a lung infection. To learn more, see the topic Sputum Culture.
  • Bronchoscopy or a needle lung biopsy are more commonly used than sputum cytology because the results provide more information about airway problems.

Other Works Consulted

  • Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.

  • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

  • Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.

ByHealthwise Staff
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Specialist Medical ReviewerRobert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology

Current as ofSeptember 9, 2014

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WebMD Medical Reference from Healthwise

Last Updated: September 09, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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