dermis One of two main layers that make up the skin. The dermis is the second layer, which contains the roots of hairs, glands which make sweat, blood and lymph vessels and nerves.

detection The discovery of an abnormality or disease in the body. 'Early

diagnosis The identification and naming of a person's disease. Many factors are taken into account, including previous medical background, symptoms, findings from a physical examination, blood tests, other laboratory tests, x-rays and possibly a biopsy . differentiated cells Mature cells that perform a specific function in the body, for example, blood cells , bone cells, or skin cells, and are clearly different from other types of cell: see cell .

digital rectal examination (DRE) A procedure in which the doctor or nurse inserts a gloved finger into the patient's rectum to examine this area. It is also possible to examine the prostate gland through the wall of the rectum.

disseminated cancer [dis-sem-i-na-ted can-cer] Cancer that is no longer confined to one part of the body, but has begun to metastasise, or spread, throughout the body.

diuretic [di-u-ret-ic] A substance that helps the body to get rid of excess fluid by passing more urine.

donor The person giving tissue or organ for transplanting. The person receiving it is the host .

duct A small tube in the body, usually one that carries the substances secreted from glands . In the breast , the milk ducts carry milk from the milk sacs to the nipple.

ductal carcinoma [duc-tal car-ci-no-ma]see intraductal carcinoma .

duodenum The first part of the small bowel. It receives bile from the gall bladder and pancreatic juice from the pancreas .

dysplastic moles [dys-plas-tic] Abnormal moles that are not cancer but may turn into cancer. Also called dysplastic naevi.