The respiratory system is divided into the upper and lower respiratory tracts. The upper respiratory tract consists of the nasal cavities, the nasopharynx, and the larynx; the lower respiratory tract consists of the trachea and the lungs.

Cytologic studies of sputum, bronchial specimens, and tissue are important as diagnostic aids because of the frequency of cancer of the lung and the relative inaccessibility of this organ. Also detectable are cell changes that may be related to the future development of malignant conditions and to inflammatory conditions.

Sputum is composed of mucus and cells. It is secreted by the bronchi, lungs, and trachea and is therefore obtained from the lower respiratory tract (bronchi and lungs). Sputum is ejected through the mouth but originates in the lower respiratory tract. Saliva produced by the salivary glands in the mouth is not sputum. A specimen can be correctly identified as sputum in microscopic examination by the presence of dust cells (carbon dust–laden macrophages). Although the glands and secretory cells in the mucous lining of the lower respiratory tract produce up to 100 mL of fluid daily, a healthy person normally does not cough up sputum.

Bronchial specimens are usually obtained through a bronchoscopy procedure. During the procedure, lung tissue may be obtained by brushing or suctioning.

Lung tissue for biopsy can be obtained through a bronchoscopy (called a transbronchial biopsy), needle aspiration, or by a surgical procedure (thoracoscopic or open procedure). Tissue specimens that are obtained are immediately placed in a container with 10% buffered formalin solution and transported to the laboratory.

Procedures

1. Procedure for obtaining sputum:

   1. Be aware that the preferred material is an early-morning specimen. Usually, three specimens are collected on 3 separate days.

   2. Have the patient inhale air to the full capacity of the lungs and then exhale the air with an expulsive deep cough.

   3. Have the patient cough the specimen directly into a wide-mouthed, clean container containing 50% alcohol. (Some cytology laboratories prefer the specimen to be fresh if it will be delivered to the laboratory immediately.) If microbiologic studies are also ordered, the container must be sterile, and no fixative should be added.

   4. Cover the specimen with a tight-fitting, clean lid.

   5. Label the specimen with the patient’s name, date and time of collection, test(s) ordered, and sequence of specimen (one, two, or three) and send immediately to the laboratory.

2. Procedure for obtaining bronchial secretions:

   1. Obtain bronchial secretions during bronchoscopy (see Chapter 12). Diagnostic bronchoscopy involves removal of bronchial secretions and tissue for cytologic and microbiologic studies.

   2. Collect secretions obtained in a clean container and take to the cytology laboratory. If microbiologic studies are ordered, the container must be sterile.

3. Procedure for obtaining bronchial brushings:

   1. Obtain bronchial brushings during bronchoscopy.

   2. Smear the material collected directly on all-frosted slides and immediately fix, or place the actual brush in a container of 50% ethyl alcohol or saline and deliver to the cytology laboratory.

4. Procedures for bronchopulmonary lavage:

   1. Use bronchopulmonary lavage to evaluate patients with interstitial lung disease.

   2. Inject saline into the distal portions of the lung and aspirate back through the bronchoscope into a specimen container. This essentially “washes out” the alveoli.

   3. Take the fresh specimen directly to the laboratory. A total cell count and a differential cell count are performed to determine the relative numbers of macrophages, neutrophils, and lymphocytes.

5. Procedure for percutaneous FNA of lung:

   1. See Fine-Needle Aspirates: Cytologic (Cell) and Histologic (Tissue) Study.

   2. Remember that the test may be done at the bedside in a designated area, usually under local anesthesia. Obtain specimens with ultrasound or CT or x-ray guidance and a tissue core biopsy needle that provides histologic and cytologic material, or use an FNA needle, which obtains cytologic material only and is useful for cancer diagnosis.

   3. Place tissue specimens in 10% formalin for fixation. Do not place specimens for culture in a fixative. Check with your laboratory for specific instructions for handling special cases.

   4. Express cytology specimens on glass slides and fix immediately in 95% alcohol. Needle rinses may provide helpful diagnostic material as well.

   5. See Chapter 1 for safe, effective, informed intratest care. See Chapter 12 on endoscopic examination (bronchoscopy).

For all procedures, see Chapter 1 guidelines for intratest care.

Abnormalities in sputum and bronchial specimens may sometimes be helpful in detecting the following:

1. Benign atypical changes in sputum, as in:

   1. Inflammatory diseases

   2. Asthma (Curschmann spirals and eosinophils may be found, but they are not diagnostic of the disease.)

   3. Lipid pneumonia (lipophages may be found, but they are not diagnostic of the disease.)

   4. Asbestosis (ferruginous or asbestos bodies)

   5. Viral diseases

   6. Benign diseases of lung, such as bronchiectasis, atelectasis, emphysema, and pulmonary infarcts

2. Metaplasia (the substitution of one adult cell type for another); severe metaplastic changes are found in patients with:

   1. History of chronic cigarette smoking

   2. Pneumonitis

   3. Pulmonary infarcts

   4. Bronchiectasis

   5. Healing abscess

   6. Tuberculosis

   7. Emphysema

3. Viral changes and the presence of virocytes (viral inclusions) may be seen in:

   1. Viral pneumonia

   2. Acute respiratory disease caused by adenovirus

   3. Herpes simplex

   4. Measles

   5. Cytomegalic inclusion disease

   6. Varicella

4. Degenerative changes, as seen in viral diseases of the lung

5. Fungal and parasitic diseases (In parasitic diseases, ova or parasite may be seen.)

6. Tumors (benign and malignant)

Pretest Patient Care

1. Explain the purpose and procedure of the test. Ensure that a signed consent is in the patient’s medical record.

2. Tell the patient not to drink fixative liquid in specimen container.

3. Emphasize that sputum is not saliva. If a patient is having difficulty producing sputum, a hot shower before obtaining a specimen may improve the yield.

4. Advise the patient to brush the teeth and rinse the mouth well before obtaining the sputum specimen to avoid introduction of saliva into the specimen. The specimen should be collected before the patient eats breakfast.

5. Ensure that the patient does not take anything by mouth for at least 6 hours before a bronchoscopy or surgical procedure.

6. Warn the patient that a bronchoscopy or FNA may be uncomfortable. Manage pain with analgesic agents as indicated.

7. Provide emotional support.

8. Instruct the patient to breathe in and out of the nose with the mouth open during the procedure, if awake. The fiber optic bronchoscope is inserted through the nose or mouth; the rigid bronchoscope is inserted through the mouth.

9. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

1. False-negative results may be caused by:

   1. Delays in preparation of the specimen, causing a deterioration of tumor cells

   2. Sampling error (diagnostic cells may not have exfoliated into the material examined)

2. The frequency of false-negative results is about 15%, in contrast to about 1% in studies for cervical cancer. This high incidence occurs even with careful examination of multiple deep cough specimens.

Normal

Negative for abnormal cells or tissue

No pathogenic organisms