A biopsy procedure removes sample bits of tissue or cells to be checked in a laboratory for microscopic signs of cancer or other diseases. In the lab, the biopsy sample is stained and examined under the microscope. This examination can tell whether the tissue sample is normal, not cancerous (benign) or is cancerous (malignant). The laboratory examination can identify the type of cancer, and may be used to evaluate the chance that cancer has spread to other parts of the body. For some types of cancer, new laboratory techniques test biopsy samples for other features of the cells, such as genetic changes. This information can be used to make a more precise diagnosis and plan more individualized therapy.
A biopsy also can identify the causes of inflammations and infections.