A biopsy is a test to take small
pieces of tissue from the body. The tissue is then looked at with a microscope. A
biopsy is not often done for kidney cancer. In most cases, imaging tests and surgery
give all the information needed to diagnose and treat the cancer. But in some cases,
a biopsy may be done to confirm a diagnosis of kidney cancer. It can also give more
information to help your healthcare provider decide which treatment is best.
During a biopsy, your skin is
numbed. A thin needle is then inserted through your skin to remove fluid or small
pieces of tissue from your kidney. Your healthcare provider then sends the sample to
a specialist, called a pathologist. The pathologist then looks for abnormal cells
under a microscope. It often takes several days for the results of a biopsy to come
The difference between an FNA and a biopsy can be subtle. An FNA involves sucking (aspirating) a small amount of tissue or fluid through a needle using a syringe. The needle used for FNA biopsy is thinner than the ones used for routine blood tests. The needle used in core biopsies is larger than that used in an FNA. It removes a small cylinder of tissue.