About non-melanoma skin cancer
What your skin does
The skin is the outer covering of your body. It protects your body from injury and infection and it protects you from the heat too. It also helps to control your body temperature and get rid of waste matter through your sweat glands.
The skin has two main layers. These are the outer layer and the inner or deeper layer . The outer layer has three types of cells. The first are flat, scaly cells called squamous cells. Below the squamous cells are rounder cells called basal cells. The cells that give skin its colour are in between the basal cells. These cells are called melanocytes.
The deepest layer called the dermis has blood and lymph vessels, hair roots and sweat glands.
What is skin cancer?
Cells do not behave as normal. They keep on growing even when there is no need and will form a tumour. If a malignant tumour is not treated, it will affect how the skin works.
How common is skin cancer?
Skin cancer is the most common cancer in Ireland. In 2017 it is estimated that there were an average of 10,857 skin cancers and 1,092 melanoma cases. But numbers are rising each year. More men than women develop skin cancer probably because they work outdoors more and play sport.
Types of skin cancer
There are different types of skin cancers. Basal cell carcinoma, Squamous cell carcinoma and other less common skin cancers such as Kaposi sarcoma, Merkel cell Cancer and lymphoma of the skin. Melanoma is a rare type of skin cancer which affects the deep cells in the deepest layer of the epidermis.
Basal cell carcinoma (BCC)
This is a cancer of the cells at the base of the epidermis (the outer layer of the skin). It is the most common type of skin cancer. If left untreated it can form an ulcer, known as a rodent ulcer. It can look like a pearly or waxy bump on your face, ears or neck.
Or else it can be a scar-like change to the skin on your chest or back that is flat, flesh-coloured or brown. In general, basal cell cancers do not spread to other tissues and organs.
Squamous cell carcinoma (SCC)
This is a cancer of the squamous cells, which are nearest the surface of your skin.
Often squamous cell cancer looks like a firm red lump on your face, lips, ears, neck, hands or arms. Or it can be a flat lump with a scaly, crusted surface on your face, ears, neck, hands or arms. It is rare for this type of cancer to spread. It is the second most common cancer in Ireland.
For more information, see our Understanding non-melanoma skin cancer booklet.
Less common skin cancers
There are other skin cancers. These are quite rare.
Kaposi sarcoma - This skin cancer develops in the skin's blood vessels and causes red or purple patches on the skin or mucous membranes. It affects people with weak immune systems, such as those with AIDS or those taking medications that affect their immune system.
Merkel cell carcinoma - This cancer forms firm, shiny lumps on or just beneath the skin and in hair roots. These may be red, pink or blue in colour. Merkel cell cancer is usually found on the head, neck, arms and legs.
Lymphoma of the skin - This is caused by the uncontrolled growth of a type of white blood cell within the skin called a T-cell.
There are some skin conditions that can lead to cancer if not treated. These are known as precancerous conditions or pre-malignant changes.
This is also known as squamous cell carcinoma in situ. In situ means that the cancer is only in the inner skin layer (epidermis) where it began. It looks like scaly red patches that may be crusted.
This is also known as solar keratosis. It is a precancerous problem caused by too much sun.
It causes small rough spots that may be pink-red or flesh coloured. They can appear on the face, ears, back of hands and arms of middle-aged or older people with fair skin.