bacteria [bac-te-ri-a] (sing. bacterium) A widely distributed group of microorganisms which live in soil, water, air, plants, animals and humans. Many do not harm their hosts, and some are actively helpful. But some cause disease by producing poisons. 

barium [bar-i-um] The common name for barium sulphate. Often used in x-rays of the gastrointestinal tract because it shows up clearly on x-rays (is radio-opaque). Before the x-ray is taken, the barium is swallowed or introduced into the bowel via the anus , depending on the part of the gut being investigated. When the x-ray is taken, the barium highlights the shape of the gut. 

barium enema [bar-i-um en-e-ma] Barium sulphate is passed into the lower bowel through the anus. X-rays are then taken and the barium clearly outlines the bowel, showing up any abnormalities. 

basal cell carcinoma (BCC) [ba-sal cell car-ci-no-ma] The most common and least dangerous type of skin cancer. BCC grows slowly and rarely spreads. It usually appears on the face as a small round or flattened lump in the skin. It will be red, pale or pearly in colour, easily detected and readily cured if treated promptly. If left untreated, it may form deep ulcers sometimes known as rodent ulcers.

BCG Bacillus Calmette-Guerin, a bacterium responsible for tuberculosis, which is used to treat some bladder cancers.

benign Benign cells are not able to spread like cancer cells. 

biopsy [bi-op-sy] The removal of a small sample of tissue from the body for examination under a microscope to help in diagnosing a disease. A needle biopsy, which can be done in a doctor's rooms, involves using a fine needle to suck up a few cells. An open biopsy (or surgical biopsy) involves a small operation, and is usually done under general anaesthetic : see diagnosis , frozen section . 

bladder A sac with an elastic wall of muscle; found in the lower part of the abdomen. The bladder stores urine until it is passed from the body. It forms part of the urinary tract .

bladder reconstruction The surgical creation of a new 'bladder' from part of the bowel. 

blood The fluid that circulates throughout the body via arteries and veins. It carries food, oxygen, hormones and other chemicals to the body's cells, and helps remove waste products from the cells. It is also important in fighting infection. Blood consists of various different types of blood cells and platelets suspended in a liquid called plasma . Plasma also contains substances to make blood clot, to prevent bleeding. An average adult male has about 5 litres of blood: see white blood cells , red blood cells .

blood cells Any of the cells that form part of blood . There are two main types: red blood cells (erythrocytes) which make up the vast majority, and white blood cells (leucocytes). Most blood cells are formed in the bone marrow ; a few are formed in the spleen and lymph glands . Also known as blood corpuscles. 

blood count Numbers of the different types of blood cells present in a given volume of blood . Usually the red blood cells (erythrocytes) and white blood cells (leucocytes) are counted, and sometimes the platelets . Normally each cubic millimetre of blood contains about 5 million red blood cells in males, and 4.5 million in females. A complete blood count (CBC) checks all of these. The level of haemoglobin may also be checked. A differential blood count counts the different types of white blood cells present. A full blood examination (FBE) is a more extensive test.

blood type Red blood cells have distinguishing features which enable them to be identified into groups. The four main types are A, B, AB, and O. Each person has only one type, referred to as their blood group. Before a blood transfusion , both donor and patient blood must be typed, then cross-matched to ensure they are compatible . For bone marrow transplants, it is necessary to type white blood cells to ensure that the donor and recipient are compatible. 

bone marrow Soft, spongy material that fills the cavities inside bones. Bone marrow produces most of the body's blood cells , so disease of the bone marrow also affects the blood.

bone marrow biopsy The removal of a small amount of bone marrow for examination under the microscope.

bone marrow transplantation The replacement of diseased bone marrow with healthy bone marrow or to regenerate bone marrow that has been destroyed by high dose chemotherapy . This may be done to treat acute leukaemia. Firstly, high doses of chemotherapy and sometimes radiotherapy are given to destroy the diseased (leukaemic) bone marrow. This is then replaced with new, healthy bone marrow. An autologous transplant uses the patient's own bone marrow, collected when the disease is under control (in remission ) and stored for use when the disease becomes active. In an allogeneic transplant, the new bone marrow is obtained from a compatible donor, usually a brother or sister: see tissue typing , stem cell . 

bone scan A picture of the bones that can show cancers, other abnormalities and infection. When a mildly radioactive substance is injected, cancerous areas in the bone pick up more of the substance than normal bone. These show up as hot spots (darkened areas) on pictures taken with a special camera. Most of the radioactive material is gone from the body within a few hours: see nuclear medicine . 

bowel Also called the intestine or gut; the part of the gastrointestinal tract between the stomach and the anus . The bowel is a tube about 8 metres long that lies curled up in the abdomen. It completes the digestion and absorption of food, and gets rid of the remaining wastes. It is divided into two main parts: the small intestine and the large intestine (also called the large bowel ). The small intestine consists of three parts: the duodenum, jejunum, and the ileum. Then comes the large intestine, made up of the colon and the rectum , and ending at the anus . 

bowel cancer A cancer that starts on the inside wall of the bowel. The vast majority of bowel cancers develop in the large bowel. They are often known as colorectal cancer. Bowel cancer is the second most common cancer for both males and females in South Australia. It is uncommon under the age of forty, and is slightly more common in men than in women. Where possible, treatment is surgery, with or without radiotherapy or chemotherapy. Surgery sometimes involves creating a colostomy (an artificial opening for the bowel on the wall of the abdomen), but in about 90 per cent of cases this is either not necessary or only a temporary measure.

 

brachytherapy [bra-chy ther-a-py] The use of radioactive implants to treat cancer; a form of radiotherapy . 

brain tumour Brain tumours may be benign (not cancerous) or malignant (cancerous). Malignant brain tumours are comparatively rare, but are the most common cancer in children; they also occur in young adults. There are various types, named according to the type of cells involved; the outlook (prognosis ) for different types varies considerably. In adults, the main types are glioblastoma, meningioma, and astro-cytoma. In children, the main types are medulloblastoma, astrocytoma, glioblastoma, ependymoma, and cranio-pharyngioma. Brain tumours are treated with surgery and/or radiotherapy . The brain is also a common site for secondary tumours that have come from a cancer elsewhere in the body. These are known as cerebral (or brain) secondaries; they are not true brain tumours.

breast The gland in a woman that produces milk. Each breast consists of a number of lobes (divisions) which contain milk sacs where the milk is produced. The lobes are surrounded by fatty tissue. Milk ducts (small pipes) lead from the lobes and join together to form fifteen or twenty larger ducts which carry milk to the nipple.