Definition: A biopsy is a medical procedure that removes a piece of tissue (for example, a piece of lung or liver tissue), so it can be evaluated by a pathologist. Usually this involves looking at it under a microscope but can include using other tests too.
The biopsy specimen is collected using surgery, endoscopy or a needle. If a needle is used (a needle biopsy), a long, hollow needle is pushed through the skin in to the targeted organ or tissue. A small piece of the tissue is collected and removed from the needle for testing.
A biopsy often confirms a diagnosis. It is also helpful for assessing the degree of damage and cause of disease. For these reasons, they are frequently used in diagnosing cirrhosis of the liver. For more information, read "What Is a Liver Biopsy?" and "Diagnosing Cirrhosis Without a Biopsy."
