Biopsy

GoBiopsy is the removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

What is Biopsy?

Biopsy is a medical test that involves removal of tissue in order to examine it for disease. The tissue samples may be taken from any part of the body.

There are several types of biopsies. Some biopsies involve removing a small amount of tissue with a needle while others involve surgically removing an entire lump or suspected tumor.

Biopsies may also be performed using imaging guidance such as ultrasound, x-ray, computed tomography (CT), or magnetic resonance imaging (MRI). of Skin Biopsy

Skin biopsies are procedures done to investigate cutaneous growths or lesions. Many skin pathologies can be diagnosed by direct observation and palpation. However, there are others that require diagnostic procedures involving microscopic and histopathological examinations.

The various techniques that may be used to obtain skin biopsies include shave biopsy, punch biopsy and excisional biopsy. Skin biopsies, compared to other biopsies are relatively low-risk procedures and are associated with very few complications. However, like other biopsies, they require a consenting patient and anesthesia, typically local.

Slide tissue biopsy from skin for diagnosis in pathology laboratory. Image Copyright: Pongsak A / Shutterstock

Shave Biopsies

This technique entails the use of a curved razor or small scalpel by an experienced surgeon to minimize the risk of scarring. It is the most commonly used technique. This is because it is relatively quick to perform, cost-effective and requires simple wound care. Shave biopsies may be done superficially, or via saucerization, and produce flat specimens.

Superficial shave biopsies are mainly used to evaluate lesions that are predominantly in the epidermis of the skin. These include skin tags, warts, and squamous or basal cell carcinomas. Under local anesthetic, a thin disk of tissue is removed for examination. The area is kept moist and covered for at least 7 days to prevent significant scar formation.

 Biopsy Analysis

A biopsy involves removal of a sample of tissue from a suspected pathological lesion. The tissue may be small in amount, for example, in fine needle aspiration biopsy. Or the tissues may be large in amounts, for example, removal of the entire lesion along with healthy margins as seen in excisional biopsy.

Who performs biopsy analysis?

Biopsy analysis requires the skill of a highly trained doctor called a Pathologist. A pathologist specializes in the diagnosis of disease based on the analysis and visualizing the microscopic amounts of tissue samples under the microscope.

Processing the tissue specimen

Once the tissue is obtained for biopsy it is preserved in formalin or similar chemicals and transferred to the laboratory. This is done to preserve the structure of the tissue and prevent degradation or microbial infestation.

The tissue is then frozen into a block of wax or similar substance. The block is then sliced into microscopically thin slices. Each of the slices are as thick as a single cell. The thin slice is then placed on a glass slide. The remaining tissue is stored for further studies, if required.

The slide is then fixed (so that the tissue slice) remains attached to it and stained with special dyes. These dyes are special because they attach to certain parts of the cell giving them a characteristic appearance.

The most commonly used stain is the Hematoxylin and eosin stain (H&E stain or HE stain). This stain shows up as blue color in the nucleus of the cell and the rest of proteins and body of the cell stains pink or red. Other stains include PAS, MVB, Congo Red etc.

Preparation of report

Staining and examination under the microscope enables the pathologist to see the exact structure of the tissue sample. Based on the findings, the Pathologist prepares a written report that will list any abnormalities or important findings.

Discussion and planning treatment

After the preliminary report from the pathologist the report needs to be co-ordinated with the clinical features and findings of the diseases. The attending doctor will then explain and discuss the results of the biopsy with the patient and his or her family. Based on this the diagnosis and treatment regimen is planned for individual patients.

What is a Breast Biopsy?

There are several types of breast biopsy. The choice of which type is suitable for an individual depends on various factors. Some of these include:

The extent of suspicion of cancer of the breast tumorThe size of the tumorThe number of tumorsOther medical problemsPersonal preferences of the patient

Types of breast biopsy

The various types of breast biopsy include:

Fine needle aspiration biopsy or cytology (FNAB/FNAC)

In this procedure the pathologist or the doctor uses a very thin needle (thinner than ones used for blood tests) attached to a syringe to withdraw a small amount of tissue from the suspicious area. The tissue is placed over a glass slide, stained with special dyes and examined under the microscope.

The area of the biopsy is first numbed with a local anesthetic injection. For the procedure the doctor locates the lump by palpating it or feeling it by hand. In case the lump is not felt by hand the doctor may use imaging guidance of an ultrasound and watch the needle on a screen as it moves toward and into the mass.

Another method is to use a stereotactic needle biopsy to guide the needle. In this the computers can map the exact location of the mass using mammograms taken from 2 angles. This helps in the biopsy.

An FNAC may sometimes miss cancer if the needle does not get a tissue sample from the area of cancer cells. This may require a second FNAC or a different type of biopsy.

Core needle biopsy

This is similar to FNAC. In this the needle is slightly larger and hollow. It is used to withdraw small cylinders (or cores) of tissue from the abnormal area in the breast. This is also performed under local anesthesia.

The needle is put in 3 to 6 times to get the samples, or cores. Imaging guidance may be used for this type of biopsy as well. A stereotactic core needle biopsy may also be performed under imaging guidance.

Vacuum-assisted core biopsy

This is done by a Vacuum Assisted Device.  A hollow probe is put in through a cut over the lump. A cylinder of tissue is then pulled into the probe through a hole in its side, and a rotating knife inside the probe cuts the tissue sample from the rest of the breast.

Surgical or open biopsy

If the tumor is diagnosed using FNAC, treatment is planned accordingly. In some cases where diagnosis is not confirmed a surgical biopsy may be recommended. For this the lump may be totally or partially excised. This may also be called an open biopsy.
Open biopsies are of two types - incisional biopsies and excisional biopsies. When an entire lump 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''.

Sentinel Node Biopsy

This is biopsy of a sentinel lymph node. A sentinel lymph node is the first draining axillary lymph node from the breast. If tumor cells are detected in this node, the status of the spread of the cancer from the breast can be predicted.