COMMON SKIN CANCERS
Common Skin Cancers
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 common malignant skin tumours are:
1. 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 carcinoma.
Basal Cell Carcinoma
2. 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
A pre-malignant stage (early
stage) of this is Bowen’s Disease. It commonly presents as a scaly plaque which does not respond to treatment.
Squamous Cell Carcinoma
3. Malignant Melanoma
This is a cancer of the
pigment cells (melanocytes) in 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: -
1. it grows more
2. its surface may
have varying shades of colour
3. its surface may
be thick and irregular
4. its margin may be
5. it may show features of change over
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 history 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 nails, the palms and soles. Excessive exposure to the sun and
a history of sunburns are predisposing factors.
Melanomas have a tendency to
spread (metastasise) 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 anaesthesia 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.
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 cryotherapy, topical therapy (creams), photodynamic therapy (PDT) or radiotherapy 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 (e.g. 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 cancer specialist.
• 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 (e.g. sunscreens,
umbrellas, hats) when going out in the sun.
• Avoid smoking.
DEDICATED TO EXCELLENCE IN DERMATOLOGY
By National Skin Centre (Singapore)
Copyright (C) 1995 - National Skin Centre (Singapore)