There are many types of skin tumours/growths. Some of them are harmless and need no treatment. These are called benign tumours. Some are cancerous and must be removed early. These are called malignant tumours. Some commoner malignant skin tumours are:
1. Squamous Cell Carcinoma (SCC)
This presents as a firm irregular fleshy growth usually on sun exposed skin. The growth can increase in size giving rise to a large lump which may sometimes break down to form an ulcer. If untreated, the cancer may spread to the surrounding lymph nodes. Squamous cell carcinoma usually appears in elderly patients. Chronic sun exposure is an important contributing factor in the development of this type of skin cancer. Some people who have had chronic arsenical exposure in the past may also develop these cancers later in life.
2. Basal Cell Carcinoma (BCC)
This is a slow growing skin cancer. It is often painless. The cancer can present as a longstanding ulcer with a shiny or pearly raised margin. The cancer is often pigmented in Asian races. This cancer commonly appears on the face. If left untreated, the cancer can slowly destroy the surrounding skin and underlying structures such as muscle and bone. Chronic sun exposure is also a predisposing factor in the development of basal cell carcinomas.
3. Malignant Melanoma
This is a cancer of the pigment cells (melanocytes) of the skin, and is a dangerous type of skin cancer. It often presents as a dark brown or black skin growth or ulcer. It may look like ordinary moles. But unlike the common mole:-
- it grows more rapidly
- its surface may have varying shades of colour
- its surface may be thick and irregular
- its margin may be irregular
- it may show features of change over time
Melanomas may occur spontaneously, or they may arise from a pre-existing “normal” mole. People born with large moles (giant congenital nevi) or have positive family histories of melanoma are at increased risk.
Melanoma is more common among Caucasians and less common in Asians and people with a darker skin type. It can occur on any site, including the palms and soles. Excessive exposure to the sun and a history of sunburns are predisposing factors.
Melanomas have a tendency to spread (metastasize) to surrounding lymph nodes or other parts of the body, leading to morbidity and mortality. As such, early detection and treatment of this condition is important.
Diagnosis of skin cancers
Any skin lesion that is progressively enlarging should be assessed and examined by a trained doctor. Contrary to popular belief, malignant skin tumours do not always cause pain, so this symptom is not reliable. If a skin cancer is suspected, your doctor may advise and order a biopsy under local anaesthetic for microscopic examination. Upon confirmation of a malignant skin tumour, the doctor can assess and advise the best option for treatment. Alternatively, the entire lesion can be removed at the outset and sent for examination and confirmation of cancer.
Fig.1 Herpes Zoster (Shingles) - red patches and blisters appear in a band on one side of the body.
Fig.2 If herpes zoster affects the region around the eye, the eye itself may also be affected
The most common form of treatment of a malignant skin tumour is excision, a process which involves removing the entire skin lesion. In certain situations whereby complete excision may not be feasible, other forms of therapy such as radiotherapy, photodynamic therapy or topical therapy may be used.
After removal of a malignant skin tumour, patients will need to be followed up regularly by their doctors for a few years. This is to look out for any recurrences of the skin tumour that may occur. It also gives the doctor a chance to assess whether new skin tumours have developed in other areas. In certain situations (eg. In advanced disease, or if the skin tumour has spread to involve the lymph nodes or other organs), some patients may need to be further evaluated and managed jointly with an oncologist.
Sun exposure has been shown to be an important factor in the development of many skin tumours. Avoidance of long hours of intense sun-exposure may help to decrease the risk of skin cancers. It is advisable to use proper sun-protection (eg. sunscreens, umbrellas, hats) when going out in the sun.
DEDICATED TO EXCELLENCE IN DERMATOLOGY
By National Skin Centre (Singapore)
Copyright (C) 1995 - National Skin Centre (Singapore)