| Solar keratoses
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.
Solar keratosis on a nose
Keratoacanthoma (KA)
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.
A KA on the neck
Non Melanotic Skin Cancer
There are 2 types of this form of cancer : basal cell carcinoma (BCC)
and squamous cell carcinoma (SCC).
BCC
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
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
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.
Diagnosis
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
Boarders. 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
Elevation
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 :
Simple excision
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.
Wedge excision
A wedge shaped excision is taken when a skin cancer is near the edge of
an eyelid, nostril, lip or ear.
Skin graft
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 :
Advancement
Rotation
Bilobed
Transposition
Other surgery
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.
LN dissection
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. |
