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), other appear from unnatural growth of melanocyte cells. So both cases are based on melanocytes where they have invaded an epidermal and dermal layers of skin. There are normally about 10 to 40 lesions on 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 eyes, respiratory system, even on cortex of brain. But most of cases (~90%) appears on skin.
As mentioned earlier it is hard to detect melanoma in early stages as it may appear as benign lesion. So if there is even a little suspicion about malignant lesions, it is necessary to attend screening at 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 lungs patient may have difficulties in breathing – like astma. Melanoma in bones may appear as bone ake.