Biopsy Definition
A biopsy is a medical procedure that involves the removal of cells or tissues from the body for examination by a pathologist. The pathologist examines the tissue under a microscope or performs other tests to determine if there are any abnormalities or diseases present. Biopsies can be taken from any part of the body and are used to diagnose various conditions, including cancer.
Types of Biopsy
Incisional Biopsy
An incisional biopsy is a surgical procedure in which a cut is made through the skin to remove a sample of abnormal tissue or part of a lump or suspicious area.
The tissue is then checked under a microscope for signs of disease. Incisional biopsies are used to diagnose various types of cancer, including those involving the skin, breast, muscles, and lymph nodes.
Incisional biopsies are different from excisional biopsies. In an excisional biopsy, the entire lesion or mass is removed and tested. When possible, an excisional biopsy is preferred when melanoma is suspected. An incisional biopsy only removes a sample of the suspicious tissue for diagnosis.
To prepare for an incisional or excisional biopsy, depending on the size and location of the lesion or mass, patients may be given medicine to make them sleepy.
If this is the case, they will need to fast (not eat or drink) for 6-8 hours before the test. If patients will not be sedated, typically numbing medicine such as lidocaine is used.
Excisional Biopsy
An excisional biopsy is a surgical procedure in which a cut is made through the skin to remove an entire lump or suspicious area, including a small amount of healthy tissue around it, so that it can be checked under a microscope for signs of disease. The procedure is used to diagnose breast cancer and melanoma.
When the entire tumor is removed, the procedure is called an excisional biopsy. If only a portion of the tumor is removed, the procedure is referred to as an incisional biopsy.
During an excisional biopsy, the doctor removes an entire lump or an entire area of abnormal skin, including a portion of normal skin. The amount of normal tissue taken depends on the thickness of the tumor.
After removal, the tissue is studied under a microscope to see if cancer cells are present. If cancer cells are found, other tests are done on the tissue to help plan treatment.
An excisional biopsy is usually preferred when melanoma or breast cancer is suspected because it allows for the complete removal of the abnormal area and provides enough tissue for accurate diagnosis and staging.
In some cases, if all cancer cells are removed during an excisional biopsy, no further surgery may be needed.
Needle Aspiration Biopsy
Needle aspiration biopsy is a minimally invasive procedure that involves inserting a thin, hollow needle through the skin and into the suspicious area to obtain a cell sample for diagnosis or treatment guidance. There are two types of needle biopsy techniques: fine-needle aspiration and core needle biopsy.
Fine-needle aspiration uses a thin, hollow needle to draw cells from the body, while core needle biopsy uses a wider needle than a fine-needle aspiration to extract a sample of tissue for testing.
Before the procedure, imaging tests such as an ultrasound, CT scan, or MRI may be used to guide the biopsy needle to the right spot.
The biopsy may be performed by a doctor, pathologist, or radiologist. If medications are needed to relax you during the procedure, they will be administered through a vein in your arm.
During the procedure, you may experience mild discomfort such as pressure in the area being biopsied. Once enough cells are collected, the needle is withdrawn and the process is complete.
There is no one standard preparation before fine-needle aspiration. However, you may be asked to stop taking aspirin or other blood thinners several days before the test.
For breast FNA specifically, patients lie on their backs and must remain still during the procedure. Ultrasound may be used to guide the placement of the needle and patients may feel some pressure from it as the needle is inserted.
Once in place, doctors use a syringe to pull out small amounts of tissue and/or fluid which might be repeated several times until enough cells are collected.
Cancer Biopsies
A biopsy is a procedure to remove a piece of tissue or a sample of cells from the body so that it can be tested in a laboratory.
Biopsies are most commonly done to look for suspected cancer, but they can also be done to identify other conditions such as anemia, certain blood cell conditions, Crohn’s disease, and other inflammatory illnesses. There are different types of biopsies that doctors use to look for cancer.
Needle biopsies are the most common type of biopsy. In this type of biopsy, a needle is used to access the suspicious tissue.
For instance, in a fine needle aspiration biopsy, the doctor inserts a very thin, hollow needle through the skin to collect a sample of cells and sometimes fluid for examination. A core needle biopsy is used to remove larger tissue samples. This method is commonly used to check breast biopsies.
Endoscopic or laparoscopic biopsies use an endoscope or laparoscope to see inside the body. With both methods, a small cut is made in the skin and an instrument is inserted.
An endoscope is a thin, flexible tube with a camera on the tip along with a cutting tool to remove the growth and examine the sample until the cancer is no longer seen at the edges of the removed sample.
An excisional biopsy involves removing either the entire tumor (called an excisional biopsy) or part of it (called an incisional biopsy). This type of biopsy is often done using local or regional anesthesia (drugs are used to numb the area).
The time it takes to get results from a biopsy can vary. During surgery, a pathologist may read a biopsy and report back to a surgeon in minutes. Final conclusions on biopsies often take more than one week.
Biopsies for Inflammatory Diseases
Biopsies are used to diagnose inflammatory diseases in different parts of the body. For example, a biopsy of the gastrointestinal tract can detect suspected inflammatory bowel diseases like Crohn’s disease and Ulcerative colitis.
Regular biopsies are taken to assess the activity of the disease and to assess changes that appear before the lesions turn cancerous. Inflammatory skin diseases can also be diagnosed through biopsies.
For many active inflammatory conditions, a biopsy sample that includes the advancing edge of the lesion and established abnormal skin will be optimal. A 3- to 4-mm punch biopsy is considered the minimum for diagnosing inflammatory skin diseases.
The timing and location of a biopsy are important factors in obtaining an accurate diagnosis. Prior treatment with topical steroids can alter histological appearances, so attention should be directed to areas that are untreated or have been free of treatment for a period (preferably one month) prior to biopsy.
The best technique for diagnosing inflammatory skin disease is considered to be a punch biopsy. Cytokine/Chemokine assessment is also being explored as a complementary diagnostic tool for inflammatory skin diseases.
Common Biopsy Sites
Biopsies are performed in many areas of the body and for many reasons. The most common biopsy sites include breast, prostate, lung, uterus/cervix/ovary, colon and stomach, skin, bone marrow/blood/lymph node, and thyroid.
Needle biopsy is a general term that’s often used to describe inserting a special needle through the skin to collect cells from a suspicious area. Doctors call this a percutaneous tissue biopsy.
A needle biopsy is often used on suspicious areas that your healthcare provider can feel through your skin, such as breast lumps and enlarged lymph nodes.
Endoscopic or laparoscopic biopsies use an endoscope or laparoscope to see inside your body. With both of these methods, a small cut is made in your skin and an instrument is inserted. An endoscope is a thin, flexible tube with a camera on the tip along with a cutting tool to remove tissue samples.
A lung or chest nodule biopsy is performed when an abnormality of the lung is visible on an x-ray or CT scan. Lung biopsies can be performed through bronchoscopy by inserting an instrument called a bronchoscope through the patient’s mouth and into the airway to reach the area to be biopsied.
Bone marrow aspiration and biopsy are often taken from the pelvic bone which is on the lower back near the hip.
Liquid biopsy testing uses blood samples for cancer detection and monitoring treatment response. It has less risk than taking tissue samples. The liver can also be biopsied via a catheter inserted through the jugular vein (a large neck vein) to capture a tissue sample or can be biopsied surgically.
