What is Melanoma Skin Cancer and its Types?

Melanoma is a serious type of skin cancer. Melanoma develops when melanocytes start to grow out of control. It can be more serious than the other forms of skin cancer because of a tendency to spread to other parts of the body (metastasize) and cause serious illness and death. About 50,000 new cases of melanoma are diagnosed in the United States every year.  Most pigment cells develop in the skin. Melanomas can develop anywhere on the skin, but certain areas are more at risk than others. In men, it is most likely to affect the chest and back. In women, the legs are the most common site. Other common sites of melanoma include the face. 

Types of Melanoma Skin Cancer 

    1. Superficial spreading melanoma: This type accounts for about 70% of all cases of melanoma. The most common locations are the legs of women and men’s backs, and they occur most commonly between the ages of 30-50. 
    1. Nodular melanoma: About 20% of melanomas are thick, blue-black, to purplish lumps. They may evolve faster and are more likely to spread. Untreated superficial spreading melanomas may become nodular and invasive.

    2. Lentigo: Unlike other melanoma forms,lentigo maligna tends to occur on places like the face, which are exposed to the sun constantly rather than intermittently. Lentigo maligna looks like a large, irregularly shaped, or colored freckle and develops slowly.         

Early Signs of Melanoma

Cutaneous melanomas usually begin in cells known as the epidermal melanocyte: 

  • 1. Lesion asymmetry or border irregularity on moles
  • 2. Bleeding or crusting
  • 3. Recent changes in moles
  • 4. Variation of color on existing moles (though some are non-pigmented)
  • 5. Diameter over 7 millimeters
  • 6. Development of an elevated area (or palpable nodule)


Melanoma is predominantly a disease of Caucasians and is slightly more common in men than women. Primary lesions occur most commonly on the trunk in males, while most melanomas in females occur on the lower extremities.