The pleura is the membrane that lines the lungs and chest cavity. A pleural biopsy is the removal of pleural tissue for examination and eventual diagnosis.
Purpose
Pleural biopsy is performed to differentiate between benign (noncancerous) and malignant (cancerous) disease, to diagnose viral, fungal, or parasitic diseases, and to identify a condition called collagen vascular disease of the pleura. It is also ordered when a chest x ray indicates a pleural-based tumor, reaction, or thickening of the pleura.
Precautions
Because pleural biopsy—especially open pleural biopsy—is an invasive procedure, it is not recommended for patients with severe bleeding disorders.
Description
Pleural biopsy is usually ordered when pleural fluid obtained by another procedure called thoracentesis (aspiration of pleural fluid) suggests infection, signs of cancer, or tuberculosis. However, the procedure is most successful in diagnosing pleural tuberculosis (with a sensitivity up to 75%) rather than pleural malignancy (40-50% sensitivity).
The procedure most often performed for pleural biopsy is called a percutaneous (passage through the skin by needle puncture) needle biopsy or closed needle biopsy. This procedure can only sample the outer pleural membrane (parietal pleura), and the size of the tissue sample obtained is relatively small.
Although the biopsy needle itself remains in the pleura for less than one minute, the procedure takes 30-45 minutes. This type of biopsy is usually performed by a physician at bedside if the patient is hospitalized or in an outpatient setting under local anesthesia.
The actual procedure begins with the patient in a sitting position, shoulders and arms elevated and supported. The skin overlying the biopsy site is anesthetized and a small incision is made to allow insertion of the biopsy needle. This needle is inserted with a cannula (a plastic or metal tube) until fluid is removed. Then the inner needle is removed and a trocar (an instrument for withdrawing fluid from a cavity) is inserted to obtain the actual biopsy specimen. As many as three separate specimens are taken from different sites during the procedure. These specimens are then placed into a fixative solution and sent to the laboratory for tissue (histologic) examination.
Although used less frequently than the closed needle biopsy, an open pleural biopsy may be performed surgically, in the operating room, when a larger tissue sample is required. The incision is larger than that required for a closed needle biopsy, and an endotracheal tube is inserted through the windpipe to assure proper breathing during the procedure. The procedure takes two to three hours, is more invasive, and requires general anesthesia and hospitalization for one or more days. Open biopsy is sometimes performed when there is no pleural effusion (an accumulation of fluid between the pleural layers) or when a direct view of the pleura and lungs is required.
Another procedure, called thoracoscopy, involves pleural biopsy under direct visualization through a thoracoscope. This procedure is highly accurate (sensitivity as
high as 91%) in diagnosing both benign and malignant pleural disease. As in open needle biopsy, however, it requires general anesthesia and is usually used only after other diagnostic procedures fail.
Preparation
Preparations for this procedure vary, depending on the type of procedure requested. Closed needle biopsy requires little or no preparation. Open pleural biopsy, which is performed in a hospital, requires fasting (no solids or liquids) for 8-12 hours before the procedure because the stomach must be empty before general anesthesia is administered.
Aftercare
Potential complications of this procedure include bleeding or injury to the lung, or a condition called pneumothorax, in which air enters the pleural cavity (the space between the two layers of pleura lining the lungs and the chest wall). Because of these possibilities, a chest x ray is always performed after the procedure (closed or open biopsy). Also, it is important for the patient is to report any shortness of breath and for the nurses to note
any signs of bleeding, decreased blood pressure, or increased pulse rate during the recovery period.
Risks
Risks for this procedure include respiratory distress on the side of the biopsy, as well as bleeding, possible shoulder pain, infection, pneumothorax (immediate), or pneumonia (delayed). Risk increases with stress, obesity, smoking, chronic illness, and the use of some medications (such as insulin, tranquilizers, and antihypertensives).
Normal results
Normal findings indicate no evidence of any pathologic or disease conditions in the pleural cavity.
Abnormal results
Abnormal findings include tumors called neoplasms (any new or abnormal growth) that can be either benign or malignant. Pleural tumors are divided into two categories: primary (mesothelioma), or metastatic (spreading to the pleural cavity from a site elsewhere in the body). These tumors are often associated with pleural effusion, which itself may be caused by pneumonia, heart failure, cancer, or blood clot in the lungs (pulmonary embolism).
