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| Wrote for Executive knowledge Lines magazine |
There are not many who have not heard of biopsy. Some seem to add a tinge of fear to the word, especially for people whose near and dear ones has to undergo it. For a common man, biopsy is a test for determining cancer and as soon as they are ordered to get a biopsy done, some kind of tremble that they have got cancer. ‘Bio’ means living and ‘opsy’ means viewing. Thus biopsy could be said as ‘testing living tissues and determining if any disease exists or the level of the disease. The earliest biopsy techniques are said to be developed by Abulcasis in the 11th century. It was the invention of Microscope that transformed the technique of biopsy to the current heights. The term’s way in to medical dictionary began with Ernest Besnier - the French dermatologist - coining the term biopsy.
We know human body is made up of
several trillion cells. Each part of the body has cells which are specialized
and adapted to carry out definitive functions of that part of the body. The
mechanisms and behavior of these cells and changes if any are analysed with a
microscope to find out any abnormalities and if it is affected by a disease.
Biopsy – What and Why?
A biopsy is taking and analyzing a
specimen of tissues of a body part which is suspected to have a disease. Let’s
take a look at some of the circumstances that necessitates a biopsy.
- To Make a new diagnosis
Biopsy is done for functions such as
determining if a new lump in the breast is cancer, checking if the swelling of
the neck is because of TB, etc. For patients who have bleeding per rectum
especially in old aged, a tissue specimen is taken from the colon by doing a
colonoscopy examination and biopsy is carried out to determine whether it is
due to hemorrhoids, cancer, or something else.
- To confirm a suspected or established
clinical diagnosis
Scan, blood tests, or clinical
examination are used in the preliminary methods to determine a disease.
However, for 100% confirmation a biopsy is mostly necessary. For example,
intestinal cancers, thyroid tumors, etc. Even though most of the skin diseases
can be determined just by checking the skin, the accuracy of this can be done
through a biopsy - Psoriasis is one example of this. Commonly used other type
of biopsies include nerve and muscle biopsies.
- To help plan management
Biopsy enables not just determining
the disease, but also the nature of the disease. Only then appropriate
treatment modalities can be given. Hence, biopsy is most often necessitated.
- To assist with Prognosis
Pathologists are able to gauge the
nature and intensity of the disease with a biopsy. As per this report, treating
doctor can determine the best possible treatment regimen for the patients and
also predict to an extent its response in controlling the disease. This will
help them in keeping the relatives appropriately informed. Especially in cancer
treatment, this provides many benefits.
- To exclude additional diagnosis
Biopsy enables to specify the
disease and exclude others. If you take the swelling of the neck, it could be
due to a viral fever, due to infection of the throat, a symptom of TB, due to
leukemia, due to cancer of some other organ, etc. It takes a single biopsy to
determine the exact cause of the swelling.
Biopsy – How?
Mainly two methods are used to
diagnose a disease through biopsy. Cytopathology – wherein the particular cells
are individually analysed for its nature, change in architecture and end in a
conclusion. The second is Histopathology, in which tissue is taken as a whole
and evaluate.
Cytology/Cytopathology
Based on the part of body tested,
there are different methods for cytology examination. FNAC or Fine Needle
Aspiration Cytology is a familiar one for many. With this, cells from a lump or
swelling is taken with a small needle and analysed. Many patients would have
seen tissues being aspirated with a needle from the lump in breast or swelling
in the thyroid gland and taken in a glass slide. Cervical cancer is also
diagnosed many times with a Pap smear – which again is a cytological biopsy.
For this, a device resembling an ice cream scoop is used to scrub the cells,
which is put on glass slide along with special colors - Papanicolaou Stain
(shortened as Pap smear) – and analysed through a microscope. This enables
viewing the nucleus, cytoplasm, and other parts of the cell clearly and making
the diagnosis.
The advantages of cytological
examination include the easiness of doing it, the short time for making a
diagnosis (1-2 days), and lower cost. Hence, doctors consider cytological
examination as a first step of examination in most of the cases. However, the
limitations in determining treatment modalities with cytological examination
make histopathological examination a necessity.
Histopathology
Surgically removed or wide bore
needle aspirated samples from disease suspected body parts are taken for
analysis in this form of biopsy technique. Various methods are available for
this. For example, if a lump is affecting the intestine, the lump with some
normal tissues on both ends of the lump is taken and analysed – this is called resection biopsy. If a small part of a
nonhealing ulcer is cut and taken for analysis, it is called wedge biopsy. If a lump is removed
entirely and examined, it is excision
biopsy. When only a part of it is removed, it is called incision biopsy. Core biopsy is using a large needle to pierce the lump and take
small parts for examination.
Radiological techniques such as CT
or ultrasound scans are used for assisting doctors for taking biopsy examination
of lumps or diseased areas which are difficult to access. For example small
lumps in the thyroid glands which cannot be identified on normal palpation
require ultrasound-guided FNAC. Similarly in CT guided biopsy, by seing the
lesion via CT scan a sample can be taken from organs such as lungs or brain.
The specimens collected are sent to
the pathology lab in a bottle filled with formalin (10% formaldehyde) with
patient details.
These specimens are taken through
various stages of analysis by expert pathologists. The sample tissues are taken
from the formalin and cut in to small pieces which are shifted to small plastic
cassettes and packed with paraffin wax. Now it is a tissue block. Using a
Microtom, this block is sliced in to sheets of 5 microns (each micron is a
thousandth of a millimeter). Each sheet is taken in a glass slide and stained
with colored liquids like Eosin and Hematoxylin. Analysing this with a
microscope a diagnosis is made.
Even though this examination process
takes at least a week, the diagnosis is reliable. For diseases like cancer,
this is very important.
The benefit of histopathological
examination is not just disease diagnosis. If it is cancer, the type
(carcinoma, sarcoma, melanoma, lymphoma, etc.), the grade (low grade/high grade
or grade 1, 2, 3, 4), tissue differentiation (well, moderate or poor), whether
the cancer has invaded into vascular or perineural areas, whether the surgery
is complete (negative resection margins), etc. are determined through this
examination. These factors influence the future treatment modalities
significantly.
Now you know that biopsy is not just
for diagnosing cancer. Right from acne to hemorrhoids, baldness to corns and
calluses, TB to arthritis – the cause for any disease can be determined with a
biopsy. The use of special stains and the advent of Immunohistochemistry has
accelerated disease diagnosis through biopsy. It is a field where high
professional skills, expertise, technological assistance and extreme efforts
are required.
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informative....!
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