A "biopsy" is defined as "the process of removing a sample of body tissue to examine it for the presence of disease." There are many reasons for requiring a biopsy, but the most common is to help determine if cancer is present in the tissue being biopsied.
Biopsies can be done in a variety of ways. The most common types of biopsy are excisional biopsy, incisional biopsy, needle biopsy and aspiration biopsy.
Excisional biopsy means that all of the suspicious area in question is removed.
Incisional biopsy means that a part of the suspicious area in question is removed.
Needle biopsy means that a hollow needle is placed into the suspicious area and a core of tissue is removed.
Aspiration biopsy means that a very thin hollow needle is placed into the suspicious areas and, using suction, individual cells are drawn out.
What are the risks of a biopsy?
The risks vary depending on the technique and body part that is being biopsied. All biopsies have some common risks associated with almost any surgical procedure -- bleeding, pain and infection. These risks should be understood by any patient undergoing a biopsy. Another risk is that the biopsy results may be inconclusive or difficult to interpret. Additional biopsies or opinions may be required to help with this problem.
Who interprets the biopsy?
A biopsy is interpreted by a physician called a "pathologist." The tissues removed are prepared in many ways, often referred to as "staining." Preparation and staining and interpretation may require two days or more. The "stained" tissue is placed between two small pieces of clear glass (called a "slide") and then examined under a microscope.
The pathologist can look at the tissue presented and give an opinion as to whether or not it is normal. The pathologist may take into consideration the patient's medical condition and other laboratory tests and previous biopsy materials before giving a diagnosis.
How long does it take to get the results of a biopsy?
The length of time for biopsy results varies from minutes to days. A technique called "frozen section" can give results in a very short time, but it is a technique that has a higher likelihood of an incorrect or incomplete diagnosis. This technique is used almost exclusively in the operating room, where decisions have to be made immediately.
In most cases, biopsy results are obtained within five to seven days. If the biopsy material is not clear cut, delays may occur. The pathologist may need to have other pathologists look at the biopsy, or additional and/or special preparations or staining may be needed. In some cases, the slides need to be sent away to a pathologist with special knowledge or expertise of a certain problem.
What can a biopsy tell?
Some of the more common interpretations of biopsies include:
- Normal tissue, no abnormalities
- Not normal, but not cancerous or malignant (often some type of inflammation)
- Not normal, difficult to interpret
- Not normal, not cancerous, but a pre-cancerous condition
What are some of the concerns about biopsy results?
The biopsy shows no cancer (No. 1 and 2)
This finding is obviously the best for the patient, but the patient must realize that the biopsy was done because of the physician's suspicion that a disease such as cancer might exist.
A biopsy can reveal cancer, but a biopsy does not rule out the existence of cancer. If the specimen does not contain the cancer cells within it, cancer may exist somewhere else in the areas that were not biopsied.
To restate this important point, a patient could still have cancer even if the biopsies do not show it. That is why physicians will ask to follow up with patients who had negative biopsies to see how they progress. If the patient's situation remains suspicious, additional biopsies of the area in question may need to be done.
The biopsy is difficult to interpret (No. 3)
Many reasons exist for a difficult interpretation. The biopsy material may have been damaged or distorted during the biopsy, transportation or preparation. Sometimes there is just not enough tissue presented to make an accurate diagnosis. Sometimes the tissue does not have the characteristics that allow the pathologist to make a certain diagnosis. Remember, a pathologist must interpret the biopsy, and pathologists may disagree on the findings.
If the reasons for biopsy are still present, the physician will usually request that additional biopsies be performed.
The biopsy shows a "pre-cancerous" condition (No. 4)
This finding is quite common in many parts of the body (prostate, bladder, breast, or cervix, for example). This means that the tissue has some of the characteristics of a cancer or malignancy but not enough to state that cancer exists at that time. Sometimes these conditions are called "carcinoma-in-situ" or "intra-epithelial neoplasia." These findings warrant close follow-up and, in many cases, require additional biopsies at a later time. In some areas of the body (such as the bladder), the pre-cancerous situation is so strongly linked with the subsequent development of cancer that treatment is begun.
The biopsy shows cancer (No. 5)
Most biopsies are done to look for cancers or malignancies. If the biopsy specimen contains almost all normal tissue but a small area of the specimen is interpreted to have cancer, the final diagnosis will still be cancer.
Even when a pathologist interprets tissue as showing cancer, one must realize that the biopsies are interpreted and therefore, there can be disagreement among pathologists on what is cancerous and what is not. Most pathologists will show the materials to other pathologists to confirm their findings (known as "consultations"), so that the final report is usually not the result of only one pathologist looking at the materials. If the reasons for biopsy were strong and cancer is found, it is unlikely that another pathologist is going to find that no cancer exists.
Second opinions on biopsy materials can be obtained without undergoing another biopsy. The second pathologist needs only to look at the first pathologist's slides to give an opinion.