Skin cancer is the most common form of cancer. For their place of origin are derived from different embryonic layers.

In general terms when we think of skin cancer, we think of basal cell, and melanoma spinocellular with 3 or distinctive characteristics:

     * Basal Cell Carcinoma: It is slow growing (it is a long time to grow, we are able to diagnose, but in general, the diagnosis is not made). The invasion is local, there is little tendency to invade by metastasis (invade distance). It is a tumor that rarely invades for metastasis.

     * Squamous Cell Carcinoma: I months. The invasion is regional (also may have systemic invasion, for example, are forms in metastatic lung, but the most common is the regional invasion.

     * Melanoma: I months. The invasion is systemic (it is one of the tumors that quickly generates systemic invasion, moreover, is the most frequently, and here we are talking about the size, and that with smaller size is capable of generating a more rapid systemic invasion. It is a very aggressive tumor.

The skin does not age. The skin is subjected to sunlight and as a result has degenerative changes, that is the aging of the skin, the people who have never exposed their skin to the sun, so "proper", your skin does not age as such.