A needle biopsy of the pleura (pleural biopsy) may be done if thoracentesis does not uncover the cause of a pleural effusion (a fluid buildup in the space between the two layers of the pleura). First, the skin is cleaned and anesthetized as for thoracentesis. Then, using a cutting needle, a doctor takes a small sample of tissue from the pleura and sends it to a laboratory to be examined for signs of disorders, such as cancer or tuberculosis. About 80 to 90% of the time, a pleural biopsy is accurate in diagnosing tuberculosis, but it is less accurate for diagnosing cancer and other disorders.
A needle biopsy of the lung may be done if a tissue specimen needs to be obtained from a lung tumor. After anesthetizing the skin, a doctor, often using chest computed tomography (CT) or ultrasonography for guidance, directs a biopsy needle into a tumor and obtains cells or a small piece of tissue to be sent to the laboratory for analysis. If a lung infection is suspected, tissue can also be sent for culture (a procedure in which a tissue sample is placed in a container containing nutrients and the container is observed to detect bacterial growth).