The five most common types of biopsy

A biopsy is a diagnostic procedure in which part or all of the tissue in question is removed so that it can be analysed and studied with the aid of a microscope. This type of test is essential to determine the presence of certain pathologies such as cancer. But which are the most common?

Bone marrow biopsy

This type of biopsy is usually performed when there is a suspicion that cancer has originated or moved to the bone marrow. It is also often performed when certain abnormal values appear in a blood test.

The bone marrow is located inside the largest bones of the body and is where blood cells are generated.

The biopsy will help us to detect diseases such as the different types of blood cancer that exist: lymphoma, multiple myeloma or leukaemia. Although, as we have said above, other types of cancer that originated in any other organ and finally reached the bone marrow can also be detected.

The process is carried out by removing a sample of marrow with the help of an elongated needle that will extract the tissue from the back of the hip. The doctor can also perform this type of biopsy using the same procedure on another bone in the body. It is usually accompanied by local anaesthesia.

Needle biopsy

This procedure is carried out with a special needle that will allow a portion of tissue to be removed from an area that has alerted the doctor’s attention because it is suspicious. In other words: the doctor may have detected certain lumps or tumours by palpation in places such as the breasts or lymph nodes.

This kind of biopsy can be accompanied by radiodiagnostic tests, such as radiography, which would allow the needle itself to be used to remove tissue from the area in question because it cannot be palpated manually.

This procedure can be carried out by:

• Fine needle aspiration.
• With thick needle.
• Vacuum-assisted.
• Image-assisted.

Endoscopic biopsy

Endoscopy is simply the use of a long, very flexible tube with a light at its tip to allow clear visualisation of the inside of the human body. If any abnormal or suspicious areas are observed, an endoscopic biopsy is performed.

The type of biopsy will be determined by the region of the body where the suspicious area has been discovered and the tubes can be inserted through a minimal incision in the skin, urinary tract, rectum or mouth.

An example of an endoscopic biopsy would be bronchoscopy, which is performed to remove cells from the lung. Depending on the type of biopsy, sedation or anaesthesia is administered.

Skin biopsy

Another of the most common biopsies is the so-called skin biopsy. Its purpose is to extract cells from the skin surface and it is widely used to detect pathologies affecting the skin, such as cancer.

There are four types of skin biopsies:

• Excisional biopsy. A nodule or the entire abnormal area of skin is removed. The incision is usually closed with stitches.
• Biopsy by scraping. As the name suggests, the doctor will scrape the skin with a double-edged blade or scalpel. The depth of the incision will be determined by the area where it is to be performed.
• Needle biopsy. With the help of a circular tool, the surgeon will remove a small piece of skin that will go deep into the deeper layers of the skin.
• Incisional biopsy. This type of biopsy is performed with a scalpel that will allow a tiny part of the skin to be sectioned. Stitches will be applied depending on the size of the incision.

Surgical biopsy

This type of biopsy is only necessary in two cases:

• If another type of biopsy has previously proved ineffective in reaching the cells that are questionable.
• If the results of such a biopsy that has been performed previously are inconclusive or inconclusive.

There are many types of surgical biopsies, but one example would be the removal of breast lumps to determine the presence of breast cancer. This procedure is performed through a skin incision that gives access to the area where there is suspicion.

Your doctor will need to assess whether to use surgical biopsy to remove part of the abnormal area of tissue, or whether the entire suspicious area needs to be removed. This type of diagnostic test may require local or general anaesthesia, and you may need to stay in hospital for a few hours for observation.

How are biopsy samples treated?

The tissue sample obtained goes directly to the laboratory for further analysis and treatment (chemical, or by dissection and freezing).

The results will clarify whether cancer is present and also help the doctor to know where it originated and its type in just a few days. In addition, the doctor will be able to know the degree of aggressiveness, i.e. the grade, which can range from 1 to 4 and is determined once the cells have been checked with the help of a microscope.