Facts about melanoma you should know

Lesions on various skin places used to be a sign of beauty. But until they are benign. As known, about 50% of melanoma evolutes from benign lesions(congestion of melanocytes); others appear from abnormal growth of melanocyte cells. So both cases are based on melanocytes where they have invaded the epidermal and dermal layers of skin. There usually are about 10 to 40 lesions on the human body. Some of them are native, inborn, some of them appear during 35 – 40 years. Later some of them may disappear.

Melanoma is not only a skin disease as it can also appear in the eyes, respiratory system, even on the cortex of the brain. But most cases (~90%) appear on the skin.

As mentioned earlier, it is hard to detect melanoma in the early stages as it may appear as a benign lesion. So if there is even a little suspicion about malignant lesions, it is necessary to attend the screening at a dermatologic specialist who usually photographs suspicious lesions and then analyses according to ABCD rule. Other non-skin cases are even harder to detect. For instance, if melanoma appears in the lungs patient may have difficulties in breathing – like asthma. Melanoma in bones may appear as a bone ake.

Skin melanomas may be classified as follows:

  • Radial melanoma (about 70% of skin melanoma cases) – appears from dysplastic lesions. Melanoma progress takes up to 5 years. It can be detected by using the ABCD rule. More specific for elder ages. In early phases, melanomas spread in an upper layer of skin – the epidermis. Later it enters the vertical growth phase after then cancer becomes dangerous as it starts to invade inner tissues;
  • Nodular melanoma (about 15% of cases) – This type of melanoma rises very rapidly and is the most aggressive skin cancer type. From the beginning, this type of melanoma grows vertically up and down. So there is a danger from the beginning that melanoma will spread into inner tissues. This type of melanoma appears to be dark black, blue, grey, or red with smooth borders.
  • Lentiginous malignant melanoma – usually appears in the head and neck area more significant than 3 centimeters nonsymmetrical lesion. It takes a long time to progress – up to 20 years, in most cases in the 70s.
  • Acral lentiginous melanoma – is more common for dark-skinned people. It appears on the palms of hands and feet – especially under the nail of the first finger. It takes a short time to progress from 3 to 36 months. Most common among 60 year age.
  • Unclassified – the other up to 5% of cases.

Generally speaking, all melanomas grow in two phases: horizontal-radial and vertical. In the radial phase, the lesion spreads in the epidermis and papillary dermis without metastases. In this period patient can be easily cured. When growth enters the vertical phase lesions spread into deeper tissues through the dermis and deeper layers of skin. There begin metastases. In many cases, both phases come together. Most common metastases of melanoma are in:

  • Dermis(50 -75%)
  • Lungs(07 – 87%)
  • Liver(54-77%)
  • Brain(36 – 54%)
  • Bones(23 – 49%)
  • Digestive system(26 – 58%)
  • Kidney(35 – 48%)
  • Heart(40 – 45%).

How metastases are related to lesion size.

  • <0.75mm – regional metastases(2-3%), far metastases(2-3%);
  • 0.76-1.5mm – regional metastases(25%), far metastases(8%);
  • 1.51-4mm – regional metastases(57%), far metastases(15%);
  • >4mm – regional metastases(62%), far metastases(72%);

One of the most important criteria is the number of metastases in the lymphatic system. Depending on metastasis, there are statistics on survival from melanoma.

  • No metastases in lymph – 73% to survive 5 years;
  • 1 – 3 metastases in lymph – 55% to live 5 more years;
  • 4 metastases in lymph – 26% to live 5 more years;
  • macro metastases – 21% to life for 5 more years and 12% to live 10 more years.

So the number of metastases is proportional to survival.

When you should pay more attention to your skin lesions:

  • Elderly age people have to pay more attention as, during the age, melanoma prognosis become more critical;
  • Gender – a man, has more chances to get spread melanoma;
  • Number of lesions on the body – if there are more than the average number of lesions on the body;
  • Skin color – white-skinned people tend to have melanoma more often than dark-skinned people.

The primary and only effective cure for melanoma still is surgery when it is removed. But it is effective if there are no metastases. Otherwise, complex treatment is taken without big chances. So it is essential to diagnose melanoma in the early stages before it has spread to other tissues.


  1. Dear Sir,
    My name is Maula Fachrurrozie. I’m a student and currently doing my final assignment. I’m interested in melanoma issues, and decide to use that topic as my final assignment. I build a software that can diagnose melanoma using image processing and classification. Big Thanks for You Sir, because this blog really help me.
    But there is a problem, it’s difficult to get a lot of data(melanoma image). I search on internet, but i only get a small size and small resolution image. I need a not so high resolution,but images that have same size and scale. Would You tell me where to find good datum(melanoma image)? Or may be if You don’t mind,could You send me the datum u used please?
    Thank You Sir..

    Maula Fachrurrozie
    Informatics Engineering
    ITS Surabaya, Indonesia

  2. Prostate Cancer

    Thanks for the informative article about melanoma. It truly is hard to know whether the lesions are nothing to worry about, or are already a scary sign of skin cancer. I guess people should really go to their doctors regularly for screenings whenever they have red flags in their body about possible diseases.

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