Once a patient is suspected of having cancer as a result of physical examination or an imaging test biopsy is performed on the patient. An imaging test will only give an idea of an abnormality in tissue but a biopsy provides the doctors with a definite result of a cancerous tissue. Biopsy is the only method which gives a definite diagnosis. In biopsy a tissue sample is removed from the breast and this sample is examined under a microscope by the pathologist. The pathologist would look for characteristics typical of a cancer type in the tissue obtained to confirm cancer.
In biopsy tissue is seen under the microscope. There are different methods of removing sample from the tissue in which varying size of tissue is withdrawn, depending upon the individual medical condition of a patient.
These different biopsy techniques are described below:
The first method is “fine needle aspiration biopsy”. In these very fine needle is used to remove abnormal tissue sample for examination. This is the most minimal invasive technique with nearly no scarring due to the fine incision. This is performed under local anesthesia. The needle is directed to the lump in the breast which can be felt in physical examination. In situations when the surgeon or the radiologist performing the test are not able to feel the lump a guided biopsy is performed with the use of imaging studies as a guide for the needle insertion. Imaging can be ultrasound aided , then it is called ultrasound guided biopsy. In this biopsy the needle movement is monitored on the ultrasound monitor and the needle directed inside the breast tissue accordingly. When it is mammography aided then it is called stereotactic needle biopsy in which various mammogram images pin point the location of the abnormal tissue.
The second method is core needle biopsy in which compared to the FNA, a larger hollow needle is used. This is performed under general anaesthesia and the patient is made to lie down. In it the surgeon or the radiologist withdraws with the hollow needle several chunks of tissue (cylinder shaped) from the breast mass. So that the surgeon can remove required samples, needle is inserted more than once in the tissue. Predominantly there is no scarring at the incision site. The biopsy can be a guided biopsy in case the lump cannot be felt from outside – ultrasound biopsy or even stereotactic biopsy. Sometimes even a small metal clip is left inside in the breast to identify the abnormal cell growth site. Later if surgical intervention is done for cancer then at that time the clip is removed. Surgical biopsy as compared to needle biopsy gives a better diagnosis due to more tissue samples available for pathological testing.
Also as the cancer type can be predicted with this test it provides the doctor an opportunity to make known to the patient the treatment options available.
Vacuum assisted biopsy is the third type/ technique of biopsy. It is popularly also known as Minimmally Invasive Breast Biopsy (MIBB). This technique of biopsy is used when more tissue ( as compared to core biopsy) is required to be removed from the breast mass. The difference between this and the core needle biopsy is that in this technique a special probe is inserted in the breast and also the insertion is only done once unlike in core where a hollow needle is inserted several times. This is a modern technique in which the patient lies face down on the exam table and the breasts are placed in specific round openings in the table. This is performed under local anesthesia and the biopsy is a guided biopsy – ultrasound or mammography guided. The probe is inserted which with the help of a cutter, cuts round tissue of the required mass. This tissue is sucked out with the use of vacuum for examination. This tissue cutting can be done several times in one entry of the probe for sufficient removal of abnormal tissue. As in core biopsy a metal clip can be placed at the site for later identification of the site and the same can be removed later surgically.
The fourth technique of biopsy is incisional biopsy which is very similar to a surgery. And like a surgery it leaves a scar at the incision. It is performed by administering the patient local anaesthesis to make the breasts numb with an injection to the patient to induce drowsiness. It can be guided biopsy – mammograohy or ultrasound guided to locate the right site of abnormal cells. Also a procedure by the name of “needle wire localization” can be utilized. In it with a small hollow needle a wire is inserted which is then used to find out the right spot for the biopsy. The needle is removed and the wire locates the spot guided by ultrasound or mammography imaging. This technique is usually adopted when the incisional biopsy is not giving a definite diagnosis.
The fifth type of biopsy is excisional biopsy which is just a surgical procedure performed under anesthesia, to remove the tissue suspected of cancer in totality. Because it is a surgical procedure it leaves scar and even the recovery time is higher. This is the most involved biopsy technique in which the surgeon also removes the surrounding healthy tissue called margin from the cancer site. This may again be a guided biopsy by imaging aids like ultrasound or mammography. This type of biopsy gives concrete and definite diagnosis with no chance of false negative result as the entire mass is removed.