Biopsy
What is a biopsy?
A biopsy is a procedure performed to remove tissue or cells from the body for examination under a microscope. Some biopsies can be performed in a physician's office, while others need to be done in a hospital setting. In addition, some biopsies require use of an anesthetic to numb the area, while others do not require any sedation.
Biopsies are usually performed to determine whether a tumor is malignant (cancerous) or to determine the cause of an unexplained infection or inflammation.
How is a biopsy performed?
A biopsy can be obtained in various ways, depending on the type of specimen needed. Flexible endoscopes (flexible, fiberoptic tube with a viewing lens and lights) allow a surgeon to view the inside of the body through a small incision and take a tissue sample. Tissue samples are usually small and taken from tissue that appears changed in structure, such as a tumor.
Types of biopsies:
- endoscopic biopsy
This type of biopsy is performed through a fiberoptic endoscope (a long, thin tube that has a close-focusing telescope on the end for viewing) through a natural body orifice (i.e., rectum) or a small incision (i.e., arthroscopy). The endoscope is used to view the organ in question for abnormal or suspicious areas, in order to obtain a small amount of tissue for study. Endoscopic procedures are named for the organ or body area to be visualized and/or treated. The physician can insert the endoscope into the gastrointestinal tract (alimentary tract endoscopy), bladder (cystoscopy), abdominal cavity (laparoscopy), joint cavity (arthroscopy), mid-portion of the chest (mediastinoscopy), or trachea and bronchial system (laryngoscopy and bronchoscopy).
- bone marrow biopsy
This type of biopsy is performed either from the sternum (breastbone) or the iliac crest hipbone (the bone area on either side of the pelvis on the lower back area). The skin is cleansed and a local anesthetic is given to numb the area. A long, rigid needle is inserted into the marrow, and cells are aspirated for study; this step is occasionally uncomfortable. A core biopsy (removing a small bone ?chip' from the marrow) may follow the aspiration. - excisional or incisional biopsy
This type of biopsy is often used when a wider or deeper portion of the skin is needed. Using a scalpel (surgical knife), a full thickness of skin is removed for further examination, and the wound is sutured (with surgical thread).When the entire tumor is removed, it is called excisional biopsy technique. If only a portion of the tumor is removed, it is called incisional biopsy technique. Excisional biopsy is the method usually preferred when melanoma is suspected.
- fine needle aspiration (FNA) biopsy
This type of biopsy involves using a thin needle to remove very small pieces from a tumor. Local anesthetic is sometimes used to numb the area, but the test rarely causes much discomfort and leaves no scar.FNA is not used for diagnosis of a suspicious mole, but may be used to biopsy large lymph nodes near a melanoma to see if the melanoma has metastasized (spread). A computed tomography scan (CT or CAT scan) - an x-ray procedure that produces cross-sectional images of the body - may be used to guide a needle into a tumor in an internal organ such as the lung or liver.
- punch biopsy
Punch biopsies involve taking a deeper sample of skin with a biopsy instrument that removes a short cylinder, or "apple core," of tissue. After a local anesthetic, the instrument is rotated on the surface of the skin until it cuts through all the layers, including the dermis, epidermis, and the most superficial parts of the subcutis (fat). - shave biopsy
This type of biopsy involves removing the top layers of skin by shaving it off. Shave biopsies are also performed with a local anesthetic. - skin biopsy
Skin biopsies involve removing a sample of skin for examination under the microscope to determine if melanoma is present. The biopsy is performed under local anesthesia. The patient usually just feels a small needle stick and a little burning for about a minute, with a little pressure, but no pain.
Biopsies are obtained from the different skin layers:
- A shave biopsy generally involves obtaining tissue specimens from the thin outer layer of skin, called the epidermis.
- A punch biopsy generally involves obtaining tissue specimens from the epidermis. However, in some cases, a punch biopsy involves the dermis and subcutaneous tissue.
- An excisional biopsy generally involves obtaining tissue specimens from the deepest layer of skin, called the subcutaneous tissue.
Common biopsy sites:
- bone marrow
- breast
- gastrointestinal tract
- kidney
- liver
- lung
- lymph nodes
- skin
- thyroid
- brain
Following a biopsy, the tissue specimen is sent to one of the following areas of anatomical pathology to be examined and analyzed:
- surgical pathology
- cytology
- autopsy
