Reasons, Preparation & Procedure For Conducting a Sputum Cytology

Submitted on March 27, 2012

Importance of Sputum Cytology

Sputum cytology detects the presence of abnormal cells in a sputum or mucus sample. Sputum differs from saliva and is produced in the lungs and in the respiratory passage that leads to the lungs. Normal lung cells are present in sputum. Sputum cytology may be conducted in order to determine the presence of certain lung conditions that are noncancerous. It may also become necessary to conduct sputum cytology in lung cancer cases. The sample of sputum may be obtained through coughing or coughing after breathing in a saline mist. A sputum sample may also be obtained through a bronchoscopy.

Reasons Why It is Conducted

Sputum cytology is conducted to screen for lung cancer. This is however not done in cases where there is high risk of developing cancer of the lungs, such as in the case of smokers. Noncancerous lung conditions such as pneumonia, tuberculosis or asbestosis may also be detected through cytology of sputum.


If the sample is to be obtained at home or at the doctor's office, no advance preparation is required. If the sample is to be obtained through a bronchoscopy, the doctor must be informed regarding the intake of any medication, allergies to medications or anesthetics, bleeding problems, intake of blood thinning medication and pregnancy. Usually, the individual must stop consuming food six hours prior to the procedure. Clear liquids may be consumed up to two hours before the procedure. Specific instructions will be given by the doctor.


Three samples of sputum are obtained over a period of three days. A container will be provided, which may contain a liquid called fixative. This helps in preservation of the sample. It is advisable to collect the sputum sample immediately on waking up in the morning. After rinsing the mouth with water, the individual must take a few deep breaths and then cough a few times. Then inhaling deeply, he must cough into the container so as to obtain a sample of sputum from deep within the lungs. In a bronchoscopy, a thin instrument with a light called a bronchoscope is used to collect the sample of sputum. It is inserted into the throat through the mouth or nose and then passed into the airways that lead to the lungs.

The presence of abnormal cells in the sputum sample may be indicative of lung conditions such as inflammation, asbestosis fiber build up in the lungs, pneumonia or cancer of the lung.