A biopsy is the removal of a small piece of tissue from the body for laboratory examination. If cancer is present, the specialist who examines the tissue (pathologist) can usually tell what kind of cancer it is and identify genetic markers or hormone receptors that may help determine the most effective cancer treatment.

A tissue sample can be taken from almost anywhere on or in the body, such as the skin, stomach, kidneys, liver, and lungs. It can be done by cutting or scraping a small piece of a tumor or by withdrawing a sample of tissue with a needle and syringe. How the biopsy is carried out will depend on where the tissue sample is being taken from.

What to expect

Before a biopsy, a person may be given a medication to numb the area (local anesthesia). Others may be given medication to help them relax (sedated) or sleep (general anesthesia) during the procedure.

The technique of the procedure will vary according to the type of biopsy.

In needle biopsy, a needle biopsy, the area of the skin is cleaned and numbed. A needle, either a very thin, hollow needle (aspiration) or a slightly larger needle (core), with a tube (syringe) attached is inserted several times to obtain the tissue. Additional numbing medication may be necessary once the needle has gone through the skin into the soft tissues. Needle biopsies are often done with the visual assistance of ultrasound or CT scan (computed axial tomography scan), which guide the physician to the right area to be sampled.

Other biopsies may be done by inserting a tiny telescope into the body (closed biopsy), such as an endoscope into the throat and stomach, or a laparoscope into the abdomen. In these procedures, a small cut is made so that scope can be inserted. This instrument helps guide the surgeon to the right place to take the sample. At the end of the scope is a pinching instrument that is used to snip off a small tissue sample.

In other cases, surgery might be required to reach the tissue that needs to be sampled (open biopsy). During open biopsy, an incision is made in the skin and a sample of tissue is cut directly from an exposed area.