DIAGNOSIS OF MELANOMA
It is important to be aware that melanomas can occur anywhere on the skin surface, but they most frequently develop on the back, arms, neck, scalp and legs. It is therefore important that the entire skin surface is examined when screening for melanomas.
5 SIGNS OF A MELANOMA
Ultimately melanomas are diagnosed by microscopic examination of a biopsy specimen. Biopsying the correct mole or freckle requires one to know what the suspicious features of a melanoma are. The features of a mole/freckle that would make one suspicious of a melanoma can best be remembered by using the acronym, ABCDE (see below). If it's not possible to remember this then remember to look out for new funny looking freckles that are enlarging.
• A : Asymmetry (one side is different from opposite side)
• B : Border irregularities (jagged, uneven edge)
• C : Colour variegation (i.e, different colors within the same region)
• D : Diameter greater than 6 mm
• E : Evolution (change) in color, shape, or symptoms over time
Other abnormal features include inflammation (swelling) and bleeding or crusting (scabbing). A person who notices any of these changes should make an appointment with their doctor as soon as possible.
Specialists make use of skin microscopes called dermatoscopes to help improve the accuracy of clinical diagnosis of melanomas. Magnification of the mole or freckle allows a far better and more complete analysis which reduces the number of spots that are biopsied unnecessarily. Mole mapping takes this one step further and allows one to take magnified digital pictures of moles. These pictures are stored and can be compared with pictures taken of the same mole some months later. It is thus possible to detect subtle and early changes in the mole and improve one's ability to diagnose an early melanoma. Mole mapping is indicated when people have multiple suspicious-looking moles not just a few normal freckles.
Main Types of melanoma
NB. It’s important to note that the type of melanoma that one has does not influence prognosis.
NB. Most melanomas (90%) occur as new growths on the skin.
Only 10% of melanomas grow from existing moles or freckles. So when monitoring one’s skin one should preferentially be looking for new freckles that are enlarging. This explains why it does not make sense to remove all a person’s moles to try and prevent a melanoma from occurring because most of the time the melanoma will be a new growth.
1. SUPERFICIAL SPREADING MELANOMA
By far the commonest (70%) is called Superficial Spreading Melanoma and as the name implies it starts on the surface of the skin (in the epidermis) and enlarges. It generally takes the appearance of a funny looking freckle which is flat, irregular in
shape and has various colours ranging from pink and brown to black. It’s important to note that the commonest form of melanoma starts as a totally flat growth.
2. NODULAR MELANOMA
The common perception is that a melanoma forms a bump on the surface of the skin but this only happens five percent of the time. Melanomas that form bumps are known as
They generally grow faster than the superficial spreading variety and penetrate into the skin at an earlier stage of their development.
3. LENTIGO MALIGNA MELANOMA
Lentigo Maligna Melanoma occurs when a lentigo maligna turns cancerous. Lentigo malignas are the smudgy brown marks that commonly develop on the cheeks of elderly people.
Change within a brown mark on the face could signal the beginnings of a melanoma and a biopsy is indicated.
4. ACRAL LENTIGINOUS MELANOMA
This is a form of melanoma that occurs on the peripheries ("acral" is Greek for peripheral) such as one's hands and feet.
The classical acral lentiginous melanoma is one that occurs under the nail and can look just like a bruise under the nail.
5. AMELANOTIC MELANOMA
Rarely (5%) melanomas do not produce any pigment at all and appear as pink or reddish spots on the skin that are enlarging. These are known as Amelanotic Melanomas.
WHAT IS A BIOPSY?
If a suspicious mole is discovered it needs to be excised (biopsied) and sent to the lab for analysis. Usually the entire spot is removed under local anaesthetic in the doctor's rooms (if too large to remove without a skin graft or flap then the most sinister looking area of the mole is removed) and examined under a microscope by a pathologist to determine if precancerous or cancerous cells are present.