Transthoracic needle aspiration; Lung needle biopsy
A lung needle biopsy is the process of obtaining and examining a sample of lung tissue.
How the test is performed
- A chest x-ray or chest CT scan may be used to locate the precise spot of the biopsy. (If the biopsy is done using a CT scan, you may be lying down during the exam.)
- You sit with your arms resting forward on a table. You should maintain this position and refrain from coughing during the biopsy. The skin is scrubbed and a local anesthetic is injected.
- A small (about 1/8-inch) incision may be made in the skin, and the biopsy needle is inserted into the abnormal tissue, tumor, or lung tissue. A small specimen is removed with the needle and sent to the laboratory.
- Pressure is placed over the site. Once bleeding has stopped, a bandage is applied.
- A chest x-ray is obtained immediately after the biopsy.
The procedure usually takes 30 to 60 minutes. Laboratory analysis usually takes a few days.
How to prepare for the test
Before a needle biopsy of the lung is conducted, a chest x-ray, chest CT scan, or bronchoscopy will be performed. Sometimes a mild sedative will precede the biopsy. You must sign a consent form. It is important to remain as still as possible for the biopsy, and to refrain from coughing.
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child’s age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child’s age:
- Infant test or procedure preparation (birth to 1 year)
- Toddler test or procedure preparation (1 to 3 years)
- Preschooler test or procedure preparation (3 to 6 years)
- School age test or procedure preparation (6 to 12 years)
- Adolescent test or procedure preparation (12 to 18 years)
How the test will feel
A lung needle biopsy is preceded by a local injection of anesthetic, which will sting for a moment. You will feel pressure and a brief, sharp pain when the needle touches the lung.
Why the test is performed
A needle lung biopsy is performed when there is an abnormal condition that is near the surface of the lung, in the lung itself, or on the chest wall. The test is usually performed to diagnose relatively large abnormalities seen on chest x-ray or CT scan. Most often, the abnormality is not believed to be accessible by other diagnostic techniques, such as bronchoscopy.
Normal tissues and no microbial growth, if a culture is performed, are normal.
What abnormal results mean
- Bacterial, viral, or fungal lung infection
- Cancerous cells (lung cancer, mesothelioma)
- Immunoglobulin deposits (IgG, or rarely IgA) in the lung alveolar basement membranes (indicating immune disorders)
Additional conditions under which the test may be performed:
- Metastatic cancer to the lung
- Pneumonia with lung abscess
What the risks are
The risks include a collapsed lung, bleeding, and infection.
A needle biopsy should NOT be performed if other tests indicate the presence of:
- bullae (enlarged alveoli associated with emphysema)
- blood coagulation disorder of any type
- severe hypoxia (insufficient blood oxygenation)
- pulmonary hypertension
- cor pulmonale (enlargement of the right ventricle secondary to pulmonary hypertension that results from primary lung diseases - a type of heart failure)
Signs of a collapsed lung include:
- Shortness of breath
- rapid heart rate (rapid pulse)
- blueness of the skin (late sign).
If any of these occur, report them to the health care provider immediately.
by David A. Scott, M.D.