Overview
Biopsy by far forms the most important and conclusive test of all tests to detect a particular disease including cancer. It gives conclusive evidence of the cellular details of the tissue of the lesion or tumor.
This is because the tissue that the doctor removes from the suspected tumor or lesion is inspected directly under a microscope (by preparing the tissue on a slide) by a trained pathologist.
He can then see if any particular type of cells is present (such as cancer cells) in the suspected tissue. Some cases may require the removal of a small tissue sample with a needle while others may surgical removal of a suspicious node or tumor.
Needle biopsies are usually performed on an outpatient basis and do not require admission, while excision biopsies may require you to be admitted to the hospital.
A physician orders a biopsy when there is sufficient evidence about a disease. For example, the cancer surgeon orders it to look for cancer cells when there are suggestive symptoms and signs of cancer and when blood tests and imaging tests that are carried out give enough evidence of malignancy.
These other tests can suggest that cancer is present but only a biopsy can confirm the diagnosis of cancer.
A surgeon, interventional radiologist, or interventional cardiologist performs the biopsy to see if the suspected disease is present or how much it has progressed. The report also helps to plan or modify the treatment options.
However, a false report of this test generally occurs in 1 to 2% of surgical pathology cases.
Why is a biopsy done?
Biopsies are usually ordered to detect cancer. But, they can help diagnose several other conditions. The biopsy procedure varies but it is generally quite simple and uncomplicated and does not cause too much discomfort to the patient.
Here are a few examples where a biopsy may be ordered:
- Detection of a lump in the breast on a mammogram to rule out breast cancer
- When a mole on the skin changes its shape and begins to grow more rapidly than before to rule out melanoma
- In a person with chronic hepatitis to rule out liver cirrhosis
- In most cases, a biopsy not only helps to diagnose a disease but also helps to chart out the best line of treatment.
Types of biopsies
Different locations and different types of cancers require different types of biopsies. A tumor situated superficially in the body or a tumor situated deeper in the body requires different methods or procedures of biopsy.
1. Needle Biopsy
The tumor is properly examined physically and with the help of radiological findings to fix its exact location. A fine needle is inserted into the tumor and the tissue of the growth is aspirated. It is then sent for a histopathology examination. This type is called fine-needle aspiration biopsy.
Fine needle aspiration is indicated in tumors, which can be easily reached by the insertion of a needle. Examples include a skin lesion or a lump in the breast.
In the case of a bone marrow biopsy, a thicker needle is required to penetrate the bone, which is usually the hipbone. Bone marrow tissue is then aspirated with the help of a needle. This is indicated when blood tests for cancer show an abnormal rise in white blood cell count.
Limitations of Needle Biopsy
However, a word of caution is that fine-needle aspiration biopsy does tend to give false negative results as the portion of the growth that has been aspirated may be devoid of cancer cells. Further, repetition or repetitions of needle aspiration may have to be performed from other parts of the growth to come to a more or less confirmed diagnosis.
2. Excision Biopsy
In certain growths, a needle biopsy is not possible. A surgical or excision biopsy is then performed in which the whole tumor or its part is surgically removed for histopathological examination.
Histopathological examination is performed by a trained pathologist who examines the excised material prepared on a slide, under a microscope and gives the report. Biopsy findings will detect
- if cancer cells are present in the specimen
- will also confirm the type of cancer
- will give an idea of the stage of cancer
- will also report the presence of metastasis, if present and
- will also tell whether it is a fast or slow-growing tumor.
3. Endoscopy Biopsy
The doctor inserts a fiberoptic endoscope (a long, thin tube that has a telescope and light at its end for viewing) through a body orifice (eg. rectum) or through a small incision (eg. arthroscopy).
He views the suspicious tissue or organ and with the help of the endoscope, he obtains a small piece of the tissue for histopathology study.
Endoscopy can be of the following types:
- alimentary tract endoscopy used to study the gastrointestinal tract
- cystoscopy for the urinary bladder
- laparoscopy for the abdominal cavity
- arthroscopy to study joint cavity
- mediastinoscopy to study lymph nodes in the area between the lungs
- laryngoscopy to examine tissue in the trachea
- bronchoscopy to study the bronchial system
This procedure can be done in a hospital or in a doctor’s office and can take anywhere between five to twenty minutes.
Endoscopy may be used to test for conditions, such as anemia, bleeding, inflammation, diarrhea, or cancers.
Side effects of biopsy
A needle biopsy carries a small risk of bleeding and infection at the site where the needle was inserted. This could be accompanied by mild pain. Mild painkillers will control the pain.
There may be associated
- Fever that is usually low grade
- Pain at the needle insertion site, which is usually mild
- Swelling at the site
- Drainage of fluid from the biopsy site
- Bleeding that cannot be controlled with pressure or a bandage
What does the biopsy report contain and how long does it take?
The report of a biopsy is usually available within 2 to 3 days. For a more complicated analysis, the report may take 7 to 10 days.
A biopsy report contains the following information:
- A gross description of the biopsy sample describes where the sample was taken, and its appearance to the naked eye. It also describes the color, size, and texture of the specimen.
- The biopsy report also contains findings from the microscopic examination of the slide under the microscope. It is full of medical terms, which nonmedical people may not understand.
- Finally, the biopsy report contains the diagnosis expressed as organ or tissue from where the tissue to be examined was obtained, the type of biopsy procedure followed, and the final diagnosis, which may indicate a benign sample or malignant one in case of cancer.