A biopsy is a diagnostic procedure used by physicians to obtain a sample of body tissue for laboratory examination. Unhealthy or suspicious looking tissueis biopsied to diagnose disease. Usually, it is done to distinguish betweena benign and malignant tumor. Healthy tissue is biopsied in order to test formatches between tissue types, for transplants.
Any part of the body can be biopsied. Depending on whether the part of the body is easily accessible or deep within, there are several different ways to do the biopsy. After the biopsy specimen is obtained by the doctor, it is sentto a laboratory where it is examined microscopically by a pathologist. A pathologist is a physician who is specialized in rendering medical diagnoses byexamining fluids and tissues removed from the body. The pathologist preparesa written report, which enables the primary physician to diagnose the patient's condition.
There are several different ways to do biopsies. In an excisional biopsy, theentire organ or lump is removed. This is because, some tumors such as lymphomas (cancer of the lymphatic system) need to be examined in whole in order toget an accurate diagnosis. Another case for an excisional biopsy would be when the organ is small and lies deep within the body (such as the spleen). Cutting into it would be a risky procedure, hence doctors would opt for removalof the whole organ.
In an incisional biopsy, only a small portion of the lump is removed. This isdone routinely to distinguish between benign and malignant tumors of the soft tissues (such as muscle, fat, connective tissue).
The parts of the body with natural openings to the surface, such as the intestines, bladder, and the bronchi are biopsied using a procedure known as endoscopy. Endoscopy enables the doctor to view the inside of the body using a long flexible tube known as a scope. There is a lighted source inside the scopeand a passage to see the inside of the body. Fiberoptics is used to transmitlight and images. A fiberoptic endoscope is inserted through an opening of the body, or a small surgical incision is made on the skin and the scope is inserted. The doctor can visually examine the surface lining the organ and if anabnormality is seen, small pieces of tissue can be pinched off using forceps, attached to the scope. Depending on the organ in the body being examined, the biopsies have different names. An upper GI endoscopy refers to examinationof the esophagus, stomach and upper part of the small intestine. A colonoscopy refers to the examination of the entire large bowel, while a sigmoidoscopyexamines the lower part of the large bowel and the rectum. A bronchoscopy isused to examine the airways and a cytoscopy to examine the bladder. A colposcopy enables a gynecologist to view the cervix and the uterus.
Fine needle aspiration biopsy was considered a major advance in cancer diagnosis because it was an extremely simple procedure. A fine needle is inserted into a lump or a cyst and cells are aspirated into the syringe. This is especially useful in examining deep set tumors, because the only other alternativeto get to them is major surgery. Aspiration biopsy is generally done to see whether a cyst is solid or filled with fluid. Modern imaging techniques such as CT scans and ultrasounds are now preferred to determine this difference andaspiration biopsies are used less often.
A punch biopsy is a technique generally used by dermatologists to sample small lumps on the skin. It is a minor procedure where a small biopsy punch is used to cut out a piece of cylindrical skin (approximately 3-4 mm in diameter).A procedure called a "bone marrow biopsy" is used to examine cells of the bone marrow. In adults, the sample is usually taken from the pelvic bone. The biopsy site is numbed with a local anesthetic and a needle is inserted to deaden the membrane covering the bone. A larger rigid needle is then introduced into the marrow of the bone and cells are aspirated into the syringe. Sometimes the aspiration is followed by a "core biopsy," in which a slightly larger needle is used to extract the core of the bone.
For most biopsies, no special preparation is necessary. Local anesthetics maybe given and a mild sedative. In case of excisional biopsy, general anesthesia may be used. Biopsies can either be done as an outpatient procedure in a doctor's office or in a local hospital setting. The time for the procedure varies depending on the site and the method of tissue removal. The risks associated with biopsy are small and vary with the procedure used to obtain the tissue sample.