A biopsy is a medical procedure in which a tissue sample or a group of cells is removed for laboratory examination. There are several types of biopsies available, designed to compliment an array of different conditions and parts of the body. Many of these procedures are performed with a needle and syringe, requiring no sedation. In some cases, the removal of tissue will necessitate surgery. Biopsies are typically conducted alongside other diagnostic processes. This will yield a more accurate diagnosis. A microscopic evaluation of biopsied cells can definitively determine the presence of cancer, but imaging tests are usually needed to determine the stage and behavior of the cancer.
Needle biopsies are frequently performed to analyze growths that can be felt through the skin. Such growths may include lumps in the breasts or testes. There are four main types of needle biopsy:
- Fine-Needle Aspiration (FNA): In this procedure, a long, fine needle pierces the skin and is inserted into the suspicious tissue. A syringe is then used to extract cells from the tissue. Typically, the cells will be sent to a laboratory for a microscopic evaluation. When a cyst is drained with FNA, and the material is not sent away for laboratory evaluation, the procedure is called a cyst aspiration. FNA is relatively painless and can be performed in minutes.
- Core Needle Biopsy: When solid tissue is biopsied, or when larger amounts of tissue are needled for evaluation, a hollow core needle is used to perform the procedure. This needle will extract a column of tissue from the suspect area. Sometimes, a small incision must be made in order to make way for this larger needle. When biopsy necessitates an incision, local anesthesia is used.
- Vacuum-Assisted Biopsy: This procedure is similar to a normal core needle biopsy. However, in a vacuum-assisted biopsy, a special machine is used to draw even more cells from the suspect tissue.
- Image-Guided Biopsy: When the suspect tissue cannot be felt through the skin, but is still a candidate for a needle biopsy, an image-guided biopsy is performed. In this procedure, the standard needle biopsy is guided with the aid of various imaging technologies, such as computed tomography scan (CT scan) or ultrasound.
A skin biopsy is performed to remove cells from the skin, or other tissues on the body’s surface. Most skin cancers are diagnosed with a skin biopsy. There are several types of skin biopsy procedures available:
- Shave Biopsy: This procedure can be performed with a small scalpel or a curved razor blade. With the tool, cells are scraped form the surface of the skin, after which they are sent away for analysis. You will not need stitches after this procedure. Shaving the skin is not the same as making an incision through the skin.
- Punch Biopsy: In a punch biopsy, a physician will use rounded knife, ranging in size from 1mm to 8mm, to remove sections of the skin below the surface. Most punch biopsies are performed to extract tissues located about ¼ of an inch into the skin. Following a punch biopsy, the wound is usually stitched to ensure proper healing.
- Incisional Biopsy: This procedure is performed to extract tissues located below the skin, into the subcutaneous fat. To extract these tissues, an incision is made with an elliptical scalpel, after which the wound will be stitched.
- Excisional Biopsy: This procedure is a type of incisional biopsy in which the entire lesion or tumor is removed. In most biopsy procedures, only a portion of the suspect tissue is removed for analysis. Because an excisional biopsy removes all of the suspect tissue, it can sometimes provide curative, as well as diagnostic results. Many melanomas, though, are located on the face and cannot be completely excised in such a manner.
In this procedure, the suspect tissue is scraped using a round curette blade. Sometimes this tool is used in a skin biopsy, but it can also be used to scrape cells from bone and other internal tissues.
When suspect tissues are inaccessible using common biopsy procedures, a surgical biopsy is required. During a surgical biopsy, an incision is made through the skin, allowing the physician to access suspicious cells located within the body. This procedure is essentially the same thing as a needle, skin, or curretage biopsy; however, it utilizes a surgical incision as a means to penetrate the suspect tissue.
A Brief History of the Biopsy
- Ernest Henri Besnier, the famed French dermatologist, introduced the word “biopsy” to the medical community in 1879.
- The first biopsy used to diagnose a disease was performed in Russia in 1875 by M.M. Rudnev.
- Historical evidence suggests that the Arabs may have been performing diagnostic biopsies as early as the 12th century AD. The Arab physician Abulcasim reportedly used a needle to extract material from a goiter (a swelling of the neck due to thyroid gland abnormalities). He used this material to characterize, or primitively diagnose the goiter.