17-11-2012, 06:18 PM
Biopsy
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A biopsy is a medical test commonly performed by a surgeon
or an interventional radiologist involving sampling of cells or
tissues for examination. It is the medical removal of tissue
from a living subject to determine the presence or extent of a
disease. The tissue is generally examined under a microscope
by a pathologist, and can also be analyzed chemically. When
an entire lump or suspicious area is removed, the procedure is
called an excisional biopsy. When only a sample of tissue is
removed with preservation of the histological architecture of
the tissue’s cells, the procedure is called an incisional biopsy
or core biopsy. When a sample of tissue or fluid is removed
with a needle in such a way that cells are removed without
preserving the histological architecture of the tissue cells, the
procedure is called a needle aspiration biopsy.
Etymology
Biopsy is of Greek origin, coming from the words bio, meaning life, and opsia, meaning to see.
French dermatologist Ernest Besnier introduced the word “biopsy” to the medical community in 1879.[1]
History
One of the earliest diagnostic biopsies was developed by the Arab physician Abulcasim (1013–1107). A needle
was used to puncture a goiter, and the material issuing was characterized.
Cancer
When cancer is suspected, a variety of biopsy techniques can be applied.
An excisional biopsy is an attempt to remove an entire lesion. When the
specimen is evaluated, in addition to diagnosis, the amount of
uninvolved tissue around the lesion, the surgical margin of the specimen
is examined to see if the disease has spread beyond the area biopsied.
"Clear margins" or "negative margins" means that no disease was found
at the edges of the biopsy specimen. "Positive margins" means that
disease was found, and a wider excision may be needed, depending on
the diagnosis.
When intact removal is not indicated for a variety of reasons, a wedge of
tissue may be taken in an incisional biopsy. In some cases, a sample can
be collected by devices that "bite" a sample. A variety of sizes of needle
can collect tissue in the lumen (core biopsy). Smaller diameter needles
collect cells and cell clusters, fine needle aspiration biopsy.
Inflammatory conditions
A biopsy of the temporal arteries is often performed for suspected vasculitis. In inflammatory bowel disease
(Crohn's disease and ulcerative colitis), frequent biopsies are taken to assess the activity of disease and to assess
changes that precede malignancy.[4]
Biopsy specimens are often taken from part of a lesion when the cause of a disease is uncertain or its extent or
exact character is in doubt. Vasculitis, for instance, is usually diagnosed on biopsy.
Kidney disease: Biopsy and fluorescence microscopy are key in the diagnosis of alterations of renal
function. The immunofluorescence plays vital role in the diagnosis of Crescentic glomerulonephritis.
Infectious disease: Lymph node enlargement may be due to a variety of infectious or autoimmune
diseases.
Metabolic disease: Some conditions affect the whole body, but certain sites are selectively biopsied
because they are easily accessed. Amyloidosis is a condition where degraded proteins accumulate in body
tissues. In order to make the diagnosis, the gingival.
Analysis of biopsied material
After the biopsy is performed, the sample of tissue that was removed from the patient is sent to the pathology
laboratory. A pathologist is a physician who specializes in diagnosing diseases (such as cancer) by examining
tissue under a microscope. When the laboratory (see Histology) receives the biopsy sample, the tissue is
processed and an extremely thin slice of tissue is removed from the sample and attached to a glass slide. Any
remaining tissue is saved for use in later studies, if required. The slide with the tissue attached is treated with
dyes that stain the tissue, which allows the individual cells in the tissue to be seen more clearly.