Australia has the highest rate of skin cancer in the world and Queensland has the highest rates within Australia.
Benign Skin Conditions
Also known as sunspots. These are red, scaly areas that occur in sun exposed areas. Although benign, these can occasionally progress to squamous cell carcinoma (SCC). The presence of a solar keratosis is an indication that the skin is badly damaged and should be monitored for the development of further skin lesions.
This is a rapidly growing tumour that looks very similar to an SCC. The only definite way to determine it is not an SCC is to look at it under a microscope. A KA does not spread around the body, but may occasionally recur locally.
Non Melanotic Skin Cancer
There are 2 types of this form of cancer : basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).
This forms about 75% of skin cancer. It typically grows slowly over a period of weeks to months. If left untreated it forms a non – healing ulcer. It was originally known as a “rodent” ulcer as it slowly gnaws away at adjacent tissues and structures. It rarely spreads to other regions.
BCC usually occurs on sun exposed areas as a small round lump or an ulcer. It is usually red or pale and pearly in colour. Small blood vessels may be noticeable on its surface.
SCC is more rapidly growing than BCC. It is associated with prolonged exposure to sunlight. SCC is potentially more serious than BCC as it has a risk of spreading to other parts of the body.
SCC looks like a red, scaly spot. It can bleed easily and may ulcerate.
Melanoma can be treated successfully if diagnosed early. Only about 1 in 20 people with skin cancer will have a melanoma.
About half of melanomas develop in existing moles, the other half develop as a new lesion. Melanomas can form on any part of the body, including areas that are not exposed to the sun.
Prevention of Skin Cancer
The following may help reduce the chance of further skin cancers :
- Avoidance of the sun between 10am and 3pm, when it is at its most intense.
- Wear a wide brimmed hat
- Wear UV protection sunglasses
- Wear a long sleeved top or shirt, and long pants, both of tightly woven cotton.
- Use an SPF 30 sunscreen. Apply a thick layer, and apply regularly particularly if swimming.
- Wear protective swimwear
- Avoid tanning booths.
The symptoms of itch or bleeding are very suggestive of melanoma.
The signs that a mole may be developing into a melanoma are :
Asymmetry or a highly irregular shape
Borders. A melanoma tends to have an irregular, ragged edge
Colour – melanomas tend to have different shades of brown and occasionally blue and black
Diameter More than 6 mm is suspicious of a melanoma
Suspicious Looking Spots
Ensure any suspicious or unusual looking skin spots are checked. Look out for :
- A new spot that looks different to the surrounding spots,
- A sore that does not heal,
- A mole, spot or freckle that has changed in size, shape or colour or one that itches or bleeds.
Surgery for skin cancer
All skin cancers need to be excised with a margin of normal tissue to ensure that they are fully excised. The resultant defect can be reconstructed using some of the following :
A skin cancer is removed as an ellipse (oval). The length is usually 2 to 3 times the width in order to avoid bunching of the skin edges or dog ears. The ellipse is usually positioned such that the resultant scar will lie in a natural skin wrinkle, fold or shadow.
A wedge shaped excision is taken when a skin cancer is near the edge of an eyelid, nostril, lip or ear.
Larger defects may require additional skin to be recruited in order to cover the defect. Grafts are classified by their thicknesses :
Split – A split skin graft is a thin shaving of normal skin taken from a separate region (usually the thigh). The skin graft is then used to cover the raw area left after excision of the skin cancer. The donor area usually heals like a gravel rash over a period of 10 to 14 days.
Full - The full thickness of the skin is removed (usually as an ellipse) from an area where there is lax skin (e.g. behind the ear, neck or groin). This wound is closed by stitching the edges together. This heals as a linear scar. The graft is secured over the raw area. This thicker graft is more robust than a split thickness graft.
Composite –refers to skin, fat and cartilage being taken as a “sandwich”of tissue. All the tissues will survive if the defect to be bridged is less than 1 to 1.5 cm.
Local flap – Various geometrical shapes of skin can be used to fill in the defects left after the excision of a skin cancer. These are commonly used on the face to give excellent cosmetic results.
The types of flaps used are :
More extensive and advanced skin cancers may require further surgery. This may include :
Larger regional or free flap reconstruction
Please refer to the Upper Limb and Lower Limb pages
Lymph node mapping or Sentinel Lymph Node biopsy
This technique is undergoing extensive clinical trials at the present time. The technique samples the first lymph node or nodes that a melanoma would drain to.
If the lymph node has no melanoma then the patient is kept under surveillance. If there is evidence of melanoma in the node then the patient would undergo formal removal of the lymph nodes in that area.
Dr Belt offers sentinel lymph node biopsy to suitable patients with melanoma.
Patients with evidence of spread of skin cancer to near by lymph nodes usually undergo formal surgical removal of the lymph nodes in that region. Such regions include the groin, armpit and the neck.