What are the different types of biopsy procedures?
Excisional Biopsy
A whole organ or a whole lump
is removed (excised). These are less common now, since the development of fine
needle aspiration (see below). Some types of tumors (such as lymphoma, a cancer
of the lymphocyte blood cells) have to be examined whole to allow an accurate
diagnosis, so enlarged lymph nodes are good candidates for excisional biopsies.
Some surgeons prefer excisional biopsies of most breast lumps to ensure the
greatest diagnostic accuracy. Some organs, such as the spleen, are dangerous to
cut into without removing the whole organ, so excisional biopsies are preferred
for these.
Incisional biopsy
Only a portion of the lump is
removed surgically. This type of biopsy is most commonly used for tumors of the
soft tissues (muscle, fat, connective tissue) to distinguish benign conditions
from malignant soft tissue tumors, called sarcomas.
Endoscopic Biopsy
This is probably the most
commonly performed type of biopsy. It is done through a fiberoptic endoscope
the doctor inserts into the gastrointestinal tract (alimentary tract
endoscopy), urinary bladder (cystoscopy), abdominal cavity (laparoscopy), joint
cavity (arthroscopy), mid-portion of the chest (mediastinoscopy), or trachea
and bronchial system (laryngoscopy and bronchoscopy), either through a natural
body orifice or a small surgical incision. The endoscopist can directly
visualize an abnormal area on the lining of the organ in question and pinch off
tiny bits of tissue with forceps attached to a long cable that runs inside the
endoscope.
Colposcopic Biopsy
This is a gynecologic procedure
that typically is used to evaluate a patient who has had an abnormal Pap smear.
The colposcope is actually a close- focusing telescope that allows the
physician to see in detail abnormal areas on the cervix of the uterus, so that
a good representation of the abnormal area can be removed and sent to the
pathologist.
Fine Needle Aspiration
(FNA) biopsy.This is an
extremely simple technique that has been used in Sweden for decades but has
only been developed widely in the US over the last ten years. A needle no wider
than that typically used to give routine injections (about 22 gauge) is
inserted into a lump (tumor), and a few tens to thousands of cells are drawn up
(aspirated) into a syringe. These are smeared on a slide, stained, and examined
under a microscope by the pathologist. A diagnosis can often be rendered in a
few minutes. Tumors of deep, hard-to-get-to structures (pancreas, lung, and
liver, for instance) are especially good candidates for FNA, as the only other
way to sample them is with major surgery. Such FNA procedures are typically
done by a radiologist under guidance by ultrasound or computed tomography (CT
scan) and require no anesthesia, not even local anesthesia. Thyroid lumps are
also excellent candidates for FNA.
Punch Biopsy
This technique is typically
used by dermatologists to sample skin rashes and small masses. After a local
anesthetic is injected, a biopsy punch, which is basically a small (3 or 4 mm
in diameter) version of a cookie cutter, is used to cut out a cylindrical piece
of skin. The hole is typically closed with a suture and heals with minimal
scarring.
Bone Marrow Biopsy
In cases of abnormal blood counts, such as unexplained
anemia, high white cell count, and low platelet count, it is necessary to
examine the cells of the bone marrow. In adults, the sample is usually taken
from the pelvic bone, typically from the posterior superior iliac spine. This
is the prominence of bone on either side of the pelvis underlying the
"bikini dimples" on the lower back/upper buttocks. Hematologists do
bone marrow biopsies all the time, but most internists and pathologists and
many family practitioners are also trained to perform this procedure.
This part of procedure, the aspiration, is usually followed by the core biopsy, in which a slightly larger needle is used to extract core of bone. The calcium is removed from the bone to make it soft, the tissue is processed and tissue sections are made. Even though the core biopsy procedure involves a bigger needle, it is usually less painful than the aspiration.
This part of procedure, the aspiration, is usually followed by the core biopsy, in which a slightly larger needle is used to extract core of bone. The calcium is removed from the bone to make it soft, the tissue is processed and tissue sections are made. Even though the core biopsy procedure involves a bigger needle, it is usually less painful than the aspiration.
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