Quite often a biopsy must be performed in order to confirm a diagnosis of certain conditions of the lung, including mesothelioma. A lung needle biopsy is a technique used to take a piece of tissue from the lung for purposes of examination under a microscope. Needle biopsies are also referred to as transthoracic needle aspiration or percutaneous needle aspiration.
How Is the Test Performed?
Doctors or technicians may look for the precise point from which to take the biopsy using either a chest X-ray or a CT scan. If a CT scan is used during the biopsy, the patient will be lying down.
A lung needle biopsy can also be done during bronchoscopy or mediastinoscopy procedures. The patient sits with his or her arms resting on a table in front of them. The patient should sit perfectly still and be sure not to cough during the procedure. The skin is scrubbed and a local anesthetic is injected, which may sting for a moment.
A 1/8-inch incision is cut into the skin and the doctor will request that the patient hold his or her breath. The biopsy needle is inserted through this incision into either the lung tissue, a tumor, or any abnormal tissue. The patient may feel pressure as the needle is inserted, and then a sharp pain as the needle touches the lung tissue. The tissue is removed and taken to a lab for study.
An X-ray of the chest is taken after the biopsy is done. The procedure can take from 30 minutes to an hour. The results may take several days.
Preparing for the Test
Patients are usually asked to refrain from eating for 6 to 12 hours before the biopsy. Doctors will often advise that patients not take aspirin, non-steroidal anti-inflammatory medications (NSAIDS), or blood thinners prior to the procedure.
Before a lung biopsy, the patient is sometimes asked to sign a consent form. Immediately before the procedure, a chest X-ray or CT scan of the chest might be given. Patients may also be given a sedative in order to help them relax.
Why Is the Test Performed?
This type of lung biopsy is done to help doctors diagnose large, obvious abnormalities discovered through imaging tests like chest X-rays or CT scans. They usually cannot be detected through other tests like bronchoscopy.
These biopsies are taken from the abnormalities that are close to the lung’s surface, in the lung, or on the wall of the chest.
A normal result means that the tissue(s) are normal.
An abnormal test generally means:
- The presence of either a bacterial, viral, or fungal infection
- The presence of cancer cells, indicative of either lung cancer or mesothelioma
- An immune disorder
This type of test may also be done to look for the existence of metastatic cancer in the lungs or for pneumonia with a lung abscess.
Lung Biopsy Risk Factors
In rare cases, a collapsed lung or pneumothorax can occur during a lung biopsy. In the case of a pneumothorax, a large tube is inserted in order to re-expand the lung. While extremely rare, air escapes from the lung and becomes trapped in the chest, in which case a pneumothorax can be life threatening.
Signs of a collapsed lung include blue discoloration of the skin, a rapid heart rate, and shortness of breath. Anyone who experiences these symptoms after a needle biopsy should report them to their doctor.
Needle biopsies are usually not recommended if the patient has:
- Pulmonary hypertension
- A blood coagulation disorder
- Certain conditions associated with emphysema