Understanding cancer terms

Benign

Not cancerous. Benign cells are not able to spread like cancer cells.

Biopsy

The removal of a sample of tissue from the body, for examination under a microscope, to assist diagnosis of a disease.

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.

Epidermis

One of two main layers that make up the skin. The epidermis is the surface layer, which contains basal cells, squamous cells - which contain keratin, a protective substance that resists heat, cold and the effects of many chemicals - and melanocytes - which produce melanin.

Genes

The tiny factors that control the way the body’s cells grow and behave. Each person has a set of many thousands of genes inherited from both parents.

Haematoma

An accumulation of blood in the tissues that clots to form a solid swelling.

Lymph nodes/lymphatic system

Lymph nodes are small, bean-shaped structures which are part of the lymphatic system. The lymphatic system is part of the immune system, which protect the body against ‘invaders’, like bacteria and parasites. It is a network of small lymph nodes connected by very thin lymph vessels, which branch into every part of the body. The lymph nodes filter the lymph to remove bacteria and other harmful agents, such as cancer cells.

Malignant 

Malignant cells can spread (metastasise) and can eventually cause death if they cannot be treated.

Melanin 

The brown pigment, produced by melanocytes, which gives the skin its colour. Its role is to protect the body against the damaging effect of the ultraviolet rays present in sunlight and tanning machines in solariums.

Melanocytes 

Cells in the epidermis and elsewhere that produce melanin.

Melanoma 

Cancer of the melanocytes. The cancer usually appears on the skin, but may affect the eye and mucous membranes. Excessive exposure to UV radiation contributes to the development of melanoma on the skin.

Metastases 

Also known as ‘secondaries’. Tumours or masses of cells that develop when cancer cells break away from the original (primary) cancer and are carried by the lymphatic and blood systems to other parts of the body.

Sentinel node

The first lymph node that a tumour drains into through the lymphatic system.

Tumour

A new or abnormal growth of tissue on or in the body.

Ultraviolet (UV) radiation

The part of sunlight that causes sunburn and skin damage. It is also produced by solariums, tanning lamps and sunbeds. Ultraviolet radiation is invisible and does not feel hot.