Breast Biopsy Health Article

Definition

A breast biopsy is the removal of breast tissue for examination under a microscope by a pathologist. This can be accomplished surgically (excisional biopsy), or by withdrawing tissue through a needle (aspiration biopsy).

Purpose

A biopsy is recommended when a significant abnormality is found which cannot be identified conclusively by imaging studies. The abnormality in question might be a finding on breast self-examination, on routine physical or gynecological examination, or on a mammogram. Signs of concern in addition to palpable lumps include:

• severe breast pain
• changes in the size of a breast or the nipple
• changes in the shape of the breast or nipple
• pitting, dimpling or redness of the breast skin.
• nipple redness, irritation or inversion of the nipple which is new
• changes in the pattern of veins visible on the surface of the breast
• some types of nipple discharge

If imaging studies are not decisive, the differentiation of cancer from a benign breast condition must be determined using a biopsy. However, in pre-menopausal women, it may be appropriate to follow a lump by physical exam for one to two menstrual cycles before considering biopsy.

Precautions

Physical exam is not sufficient for evaluating significant breast abnormalities. About 30% of abnormalities thought to be benign by physical exam turn out to be cancerous, and 60% of those thought to be malignant prove to be benign.

The type of biopsy recommended should be considered carefully. The best approach will depend upon whether the area can be felt, how well it can be seen on mammogram or ultrasound, and how suspicious it feels or appears. Specialized equipment is needed for different types of biopsy, and availability may vary. Generally, needle biopsy is less invasive and much less expensive than surgical biopsy. It is appropriate for most, but not all situations. However, some surgeons feel that it is less accurate.

Description

The least invasive of biopsy procedures is the needle biopsy. A needle biopsy removes part of the suspicious area for examination. There are two types, aspiration biopsy using a fine needle, and large core needle biopsy. Either of these may be called a percutaneous needle biopsy. Percutaneous refers to a procedure done through the skin.

A fine needle aspiration (FNA) biopsy uses a very thin needle to withdraw fluid and cells that can be studied. It can be performed in a doctor's office, clinic, or hospital. Local anesthetic may be used, but is sometimes withheld, as the injection may be more painful than the biopsy needle. The area to place the needle may be located by touch. No specialized equipment is needed. This procedure is simple and inexpensive, but FNA biopsies also have the highest rate of false negative results (i.e., no cancer is found in the sample, but cancer is present at the biopsy site). FNA is very useful for biopsy of lumps suspicious for being benign cysts by physical exam and/or ultrasound. If the contents of the cyst can be completely aspirated, prove to be non-bloody fluid, and the cyst does not recur, no further biopsy is needed.

A large core needle biopsy uses a larger diameter cutting-type needle to remove small pieces of tissue, about the size of a grain of rice. It can be performed in a clinic or hospital that has the appropriate facilities. Local anesthetic is routinely used.

Ultrasound is used to guide needle placement for some lesions. The patient lies on her back or side. After the area is numbed, a sterile gel is applied. The physician places a transducer, an instrument about the size of an electric shaver, over the skin. This produces an image from the reflection of sound waves. A special needle, usually in a spring loaded device, is used to obtain the tissue. The procedure is observed on a monitor as it is happening.

If the suspicious area is seen best with x ray, a stereotactic device is used. This means that x rays are taken from several angles. This information is input into a computer, which analyzes the data and produces an image that is used to guide the needle to the correct site. The patient may be sitting up, or she may be lying on her stomach, with her breast positioned through an opening in the table. The breast is held firmly but comfortably between a plastic paddle and a metal plate, similar to those used for mammograms. Several samples will be taken because a growth might have both benign and malignant areas in it. X rays may be taken before, during, and after the tissue is drawn into the needle, to confirm that the correct spot is biopsied. This procedure may also

be referred to as a stereotactic core biopsy, or a mammotomy. Stereotactic needle biopsies are just as successful as the mammographically guided open biopsy discussed below.

There are two types of surgical breast biopsy considered here, excisional and incisional. An excisional biopsy is a surgical procedure, where the entire area of concern and some surrounding tissue is removed. It is usually done as an outpatient procedure in a hospital or free-standing surgery center. The patient may be awake, and is sometimes given a sedative. The area to be operated on is numbed with local anesthetic. Infrequently, general anesthesia is used. An excisional biopsy itself usually takes under one hour. The total amount of time spent at the facility depends on the type of anesthesia used, whether a needle localization was done (see below), and the extent of the surgery.

If a mass is very large, an incisional biopsy may be performed. In this case only a portion of the area is removed and sent for analysis. The procedure is the same as an excisional biopsy in other respects.

If the abnormality is not palpable, a needle localization must be done before the actual surgery. After local anesthetic is administered, a fine wire is placed in the area of concern. Either mammogram or ultrasound guidance is used to place the tip of the wire in the lesion. The patient is awake and usually sitting up. The surgeon then proceeds with an open biopsy, and removes the wire from the target tissue. A mammogram of the specimen is then taken to assure the abnormality intended has been sufficiently biopsied.