Biopsy procedures used to diagnose cancer

A biopsy is a procedure to remove a piece of tissue or a sample of cells from your body so that it can be analyzed in a laboratory. If you're experiencing certain signs and symptoms or if your doctor has identified an area of concern, you may undergo a biopsy to determine whether you have cancer or some other condition.

While imaging tests, such as X-rays, are helpful in detecting masses or areas of abnormality, they alone can't differentiate cancerous cells from noncancerous cells. For the majority of cancers, the only way to make a definitive diagnosis is to use a biopsy to collect cells for closer examination.

How your doctor determines the type of biopsy you need

Your doctor determines the type of biopsy that's best for you by using several factors, including the type of cancer suspected and the location of the suspicious cells.

Types of biopsy procedures

There are five main types of biopsy procedures.

Bone marrow biopsy
During a bone marrow biopsy, your doctor draws bone marrow out of the back of your hip bone using a long needle. In some cases, your doctor may biopsy marrow from other bones in your body. Bone marrow biopsy is commonly used to diagnose blood cancers, such as leukemia, lymphoma and multiple myeloma. You receive a local anesthetic before a bone marrow biopsy in order to minimize the pain.

Endoscopic biopsy
During endoscopy, your doctor uses a thin, flexible tube with a light on the end to see structures inside your body. Special tools are passed through the tube to take a small sample of tissue to be analyzed.

What type of endoscopic biopsy you undergo depends on where the suspicious area is located. Tubes used in an endoscopic biopsy can be inserted through your mouth, rectum, urinary tract or a small incision in your skin. Examples of endoscopic biopsy procedures include cytoscopy to collect tissue from the inside of your bladder, bronchoscopy to get tissue from inside your lung and colonoscopy to collect tissue from inside your colon.

Depending on the type of endoscopic biopsy you undergo, you may receive a sedative or anesthetic before the procedure.

Needle biopsy
During a needle biopsy, your doctor uses a special needle to extract cells from a suspicious area. A needle biopsy is often used on tumors that your doctor can feel through your skin, such as suspicious breast lumps and enlarged lymph nodes. Needle biopsy procedures include:

• Fine-needle aspiration. During fine-needle aspiration, a long, thin needle is inserted into the suspicious area. A syringe is used to draw out fluid and cells for analysis.
• Core needle biopsy. A larger needle with a cutting tip is used during core needle biopsy to draw a column of tissue out of a suspicious area.
• Vacuum-assisted biopsy. During vacuum-assisted biopsy, a suction device increases the amount of fluid and cells that is extracted through the needle. This can reduce the number of times the needle must be inserted to collect an adequate sample.
• Image-guided biopsy. Image-guided biopsy combines an imaging procedure, such as X-ray, computerized tomography (CT) or ultrasound, with a needle biopsy. Image-guided biopsy allows your doctor to access suspicious areas that can't be felt through the skin, such as abnormalities on the liver or prostate. Using real-time images, your doctor can make sure the needle reaches the correct spot.

You'll receive a local anesthetic to numb the area being biopsied in order to minimize the pain.

Skin biopsy
A skin (cutaneous) biopsy removes cells from the surface of your body. A skin biopsy is used most often to diagnose skin cancers, including melanoma. What type of skin biopsy you undergo will depend on the type of cancer suspected and the extent of the suspicious cells. Skin biopsy procedures include:

• Shave biopsy. During a shave biopsy, the doctor uses a tool similar to a razor to scrape the surface of your skin. You usually don't need stitches after a shave biopsy.
• Punch biopsy. During a punch biopsy, the doctor uses a circular tool to remove a small section of your skin's deeper layers. A punch biopsy extends about 1/4 inch deep. You'll likely receive stitches to close the wound.
• Incisional biopsy. During an incisional biopsy, the doctor uses a scalpel to remove a small area of skin. Whether you receive stitches to close the biopsy site depends on the amount of skin removed.
• Excisional biopsy. During an excisional biopsy, the doctor removes an entire lump or an entire area of abnormal skin. You'll likely receive stitches to close the biopsy site.

You receive a local anesthetic to numb the biopsy site before the procedure. A spray-on solution may temporarily numb an area of your skin before a shave biopsy. For a more extensive skin biopsy, you may receive a shot of medication to numb the area.

Surgical biopsy
If the cells can't be accessed with other biopsy procedures or if other biopsy results have been inconclusive, your doctor may recommend a surgical biopsy. During a surgical biopsy, a surgeon makes an incision in your skin to access the suspicious area of cells. Examples of surgical biopsy procedures include surgery to remove a breast lump for a breast cancer diagnosis and surgery to remove a lymph node for a lymphoma diagnosis.

Surgical biopsy procedures can be used to remove part of an abnormal area of cells (incisional biopsy). Or surgical biopsy may be used to remove an entire area of abnormal cells (excisional biopsy).

You may receive local anesthetics to numb the area of the biopsy. Some surgical biopsy procedures require general anesthesia to make you unconscious during the procedure. You may also be required to stay in the hospital for observation after the procedure.

During fine-needle aspiration biopsy, a long, thin needle is inserted into the suspicious area to remove cells or fluid for analysis. Fine-needle aspiration is used to diagnose several types of cancers, including thyroid cancer.

In core needle biopsy, your doctor inserts a special hollow needle into the suspicious area and withdraws a small, solid core of tissue to send for testing. Core needle biopsy is useful for diagnosing many types of cancer, including breast cancer.

Your doctor may use an imaging technique, such as ultrasound, during a needle biopsy procedure. Using a real-time image, your doctor can guide the needle into the best position for obtaining a sample of suspicious cells. Image-guided needle biopsy allows your doctor to biopsy suspicious areas that aren't readily seen or felt through your skin, such as your prostate.

Punch biopsy is one type of skin biopsy used to collect skin cells for closer analysis. The special circular blade helps your doctor extract deeper layers of skin for testing.

Biopsy analysis and results

After your doctor obtains a tissue sample, it's sent to a laboratory for analysis. The sample may be chemically treated or frozen and sliced into very thin sections. The sections are placed on glass slides, stained — to enhance contrast — and studied under a microscope by a person who specializes in examining body tissues (pathologist) or a specialist in blood and blood-forming tissues (hematologist), or both.

The results help your doctor determine whether the cells are cancerous. If the cells are cancerous, the biopsy results can tell your doctor where the cancer originated — the type of cancer.

A biopsy also helps your doctor determine how aggressive your cancer is — the cancer's grade. The grade is sometimes expressed as a number on a scale of one to four, and is determined by how biopsied cancer cells look under the microscope. Grade 1, or low-grade cancers, are generally the least aggressive and grade 4, or high-grade cancers, the most aggressive. This information may help guide treatment options. Other special tests on the cancer cells also can help to guide treatment choices.

In certain cases, such as during surgery, a pathologist examines the sample of cells immediately and results are available to your doctor within minutes. But in most cases, the results of your biopsy are available in one or two days. Some samples may need more time to be analyzed. Ask your doctor how long to expect to wait for your biopsy results.