Biopsy Test: Why and How is it Done?

A  involves removing a small portion of tissue for medical analysis in a laboratory. It is usually recommended for identifying the root cause of medical conditions that manifest through infections and inflammations. After localizing or narrowing down the area of a suspicious growth, a biopsy can give a clearer look of the cells.

In case of suspected cancers, biopsies determine whether the tumorous growth is benign (non-malignant) or malignant. It can also diagnose changes in tissues or evaluate blood cells in a bone marrow. There are various biopsy types, depending on various factors.

Some of the primary factors that determine the type of biopsy that will be recommended are:

• the location of the tissues
• the size of the sample that will be required
• whether general or local anesthesia will be administered
• whether the required biopsy procedure will be invasive or non-invasive

A biopsy test may take anywhere from only a few minutes, as in the case of skin biopsies, to hours for more invasive procedures like a bone biopsy.

Why is a biopsy test done?

A biopsy test collects tiny parts of cells or tissues from a location that is suspected to have an infection or inflammation. The cells or tissues collected as samples are sent to a laboratory for microscopic evaluation.

The cell or tissue sample is stained and then studied for the presence of abnormalities like cancerous growths. The biopsy test can also diagnose the type of cancer and also whether it has metastasized, that is, spread to other parts of the body. Certain types of biopsies can also track genetic changes in cells, enabling more efficient treatment.

Biopsy Test: Different Types, Explained

The major biopsy types are as below:

Skin biopsy test

A small part of tissue is removed from a suspected portion of the skin with a punch tool or scalpel.

Open biopsy test

This surgery is an invasive technique that involves making an incision on the skin. The depth of the incision will depend on the complexity of the biopsy procedure and the body part on which the test will be conducted. 

Fine-needle aspiration (FNA)

A thin needle, attached to a syringe, is inserted into an organ, often in the accompaniment of computed tomography (CT) or ultrasound. These tests may be conducted together to ensure that the needle is being inserted at the accurate site. The medical expert undertaking the biopsy test sucks cells from the required location and collects them in the attached syringe. 

Core biopsy

Similar to a FNA, a core biopsy involves removing a sample of tissue but in this case, uses a wider diameter needle. This type of biopsy retrieves a larger amount of cells and tissue to be examined and is often used on breast lumps.

Endoscopy procedure

This invasive biopsy procedure involves passing a fiberoptic endoscope through an incision or a natural orifice like mouth or rectum.

This medical equipment, which has a camera installed at the inserted end, offers the medical expert a close view of the affected site. Once the abnormalities and their severity have been detected, a small tissue is removed as a sample.

Bone marrow biopsy

For bone marrow aspiration, a small quantity of aspiration or bone marrow fluid is collected for further studies at a laboratory. This may also be accompanied by taking solid tissues of bone marrow, usually secured from the back of hip bones.

Further laboratory examinations are conducted to check for the presence of abnormal cells. The size, number, and maturity of these cells are also evaluated.

Punch biopsy

A deeper sample of the skin is collected that involves all the layers of the skin – superficial parts of the fat or subcutis, dermis, and epidermis. 

Shave biopsy

Here, the top layers of the skin are shaved off while the patient is under the influence of local anesthesia. This is effective in diagnosing the prevalence of skin cancer like squamous cell skin cancers, certain basal cell cancers, and skin lesions.

Reflectance confocal microscopy (RCM)

This enables the medical professional to analyze the affected site without cutting into layers of the skin as a sample.

Prerequisites of the test

The process of preparation for a biopsy test depends on the type of test that will be done. For instance, in the case of an open biopsy procedure that will require the administration of general anesthesia, the patient needs to fast, that is, avoid the intake of food and fluids for quite a few hours before the scheduled time for a biopsy. Your doctor will guide you regarding the number of hours you need to fast before the test. 

For skin biopsies, fasting is not required. On the other hand, taking laxatives and enemas are essential for a colonoscopy. Strictly follow the advice of your doctor regarding the restrictions or medications that you should follow before a biopsy test.

Let your doctor know about your history of medical conditions and the medications that you might be taking at present or in the recent past.

These medications include OTC (over-the-counter) drugs, prescription drugs, vitamins, supplements, and herbals. Also, enlighten them about any known history of allergies. There are some medications that may alter the accuracy of biopsy test results, and hence, have to be temporarily discontinued before the test. 

Results of the Biopsy

The pathologist at the laboratory observes the collected tissue or cell under a microscope. The biopsy test indicates the exact location of the sample and the extent of the abnormalities. It also indicates the medical condition that is the underlying cause of these symptoms. Your doctor may prescribe antibiotic medications and other treatments, if necessary, based on the results of the test.

When Should it Be Repeated?

It is usually advised that patients with negative biopsy results should continue to follow up with the doctor to monitor the symptoms. Reassessment later on is usually done to eliminate the risk of recurrence or progression of a condition.

This should be followed by a repeat test, based on the extent of risk indicated in the assessment. If a fresh lesion appears or if certain blood tests, tumor markers, or inflammatory markers show positive test results, doctors may advise repeating the biopsy.

Biopsy: The Procedure

The procedure of the biopsy test depends on different factors – the type of biopsy advised, whether it will be invasive or non-invasive, whether it will require local or general anesthesia, etc. 

In the case of a needle biopsy, the relevant location from where the needle will be inserted is numbed and cleaned with an antiseptic solution. A sterile needle is inserted to remove tissues or cells as a sample.

An open biopsy, conducted under general anesthesia, involves performing a surgical incision until the organ from where tissue has to be collected. Next, tissue is cut directly from the relevant organ.

For an endoscopic biopsy, forceps are used to pinch apart a small part of tissue from the required organ. In the case of a skin biopsy, the relevant site is cleaned and numbed with an antiseptic solution. A scalpel is then used to remove a small part of the tissue. The wound site is then stitched.

Learn more about cancer diagnosis and management here.