How does surgery help to diagnose cancer?
Written by Mystic on Monday, August 04, 2008A tissue biopsy is a sample of cells, tissue or tumour that is surgically removed from a particular part of the body for examination under a microscope by a histopathologist.
If cancer cells are present the histopathologist will usually be able to diagnose the type of cancer based on the appearance of the cells under the microscope. This provides information on how the cells will behave in the future, where they may spread and their sensitivity to different treatments. Preparation and examination of the specimens can take up to several days, which explains why you may need to wait before you get your results.
Common examples of surgery for taking tissue biopsies include:
Needle biopsies: This technique is used for tumours that are close to the surface of the body, for example breast lumps, as well as tumours deep within the body, as in the pancreas, liver or kidney. A local anaesthetic (see pg 10) is placed on the skin and in the soft tissues under the skin. The tumour is pierced by a very thin needle, through which a small amount of tissue is withdrawn. During needle biopsies of internal organs, X-rays or scans guide the needle and help to ensure it is accurately positioned.
Shave biopsy: a cut is made parallel to the surface of the skin to take off a small sample of tissue under a local anaesthetic. Small skin cancers can be detected and often completely removed in this way.
Incisional biopsy: involves removing part of the tumour for diagnosis, then stitching the area up again.
Excisional biopsy: is used for tumours that are easily reached, as in the skin or lymph nodes. The entire tumour is removed.
Endoscopic biopsy: specially designed long tubes or endoscopes are passed through body passages (like the bowel or gullet). A light source at the end of the tube allows for detailed examination of the tissues inside these organs. Biopsies are taken with instruments which are either attached to the endoscopes or can be introduced through them.
During exploratory surgery, the surgeon checks the location of the disease and takes tissue samples. For example during a laparoscopy which is a surgical examination of the abdominal and pelvic organs performed under general anaesthetic. An instrument called a laparoscope is inserted through a small cut just below the navel, and samples of tissue may be taken for analysis.
A diagnostic laparotomy is a procedure used for the examination of abdominal organs under anaesthetic. The surgeon makes a cut through a part of the abdominal wall. Samples of tissue from the spleen, liver and some lymph nodes may be taken. If necessary all the visible tumour may also be removed at the same time.