Types of Melanoma

Melanoma is the eighth most common malignancy in the United States.

Melanoma, the most serious type of skin cancer, develops in the cells (melanocytes) that produce melanin — the pigment that gives your skin its color. Melanoma can also form in your eyes and, rarely, in internal organs, such as your intestines.

The exact cause of all melanomas isn't clear, but exposure to ultraviolet (UV) radiation from sunlight or tanning lamps and beds increases your risk of developing melanoma.

Limiting your exposure to UV radiation can help reduce your risk of melanoma.

The risk of melanoma seems to be increasing in people under 40, especially women. Knowing the warning signs of skin cancer can help ensure that cancerous changes are detected and treated before the cancer has spread. 

Melanoma is the eighth most common malignancy in the United States and its incidence continues to rise at a rate faster than that of any other human cancer. In the 1930s the survival rate for melanoma was abysmally low, but now 5- and 10-year survival rates are well over 80 percent. 

Signs of Melanoma

Melanomas can develop anywhere on your body. They most often develop in areas that have had exposure to the sun, such as your back, legs, arms and face. Melanomas can also occur in areas that don't receive much sun exposure, such as the soles of your feet, palms of your hands and fingernail beds. These hidden melanomas are more common in people with darker skin.

The first melanoma signs and symptoms often are:

  • A change in an existing mole
  • The development of a new pigmented or unusual-looking growth on your skin

Melanoma doesn't always begin as a mole. It can also occur on otherwise normal-appearing skin.

Types of Melanoma

There are four major types of melanoma that have distinct characteristics and potential for metastasis:

Lentigo Maligna 

This type of melanoma is more commonly found on the head and neck region. It begins as a small, asymmetric pigmented patch that has irregular borders and color variations throughout the lesion. Over time the patch gets larger and retains its asymmetry, irregular borders, and color variations. This type of melanoma may remain flat and confined to the epidermis for months to many years, but at some point will penetrate into the deeper levels of skin, increasing the potential for metastases.

Superficial Spreading 

This type of melanoma is more commonly found on the trunk, upper arms, and thighs, and is the most common form of melanoma in white races. It begins a small pigmented macule that is asymmetric, has irregular borders, and has color variations. This type of melanoma remains in the flat phase for a shorter period of time than the lentigo maligna type before it penetrates into the deeper levels of the skin.

Nodular

This type of melanoma can occur on any skin surface but is found more commonly on the trunk, upper arms, and thighs.

The nodular type of melanoma has a very short flat phase before it forms a raised nodule and penetrates into the deeper levels of the skin. This type of melanoma may ulcerate and present as a non-healing skin ulcer.

Acral-Lentiginous

This type of melanoma is more commonly found on the hands, feet, and nail beds. It is seen in all races​ but is most frequently found in dark-skinned races. It is similar to the lentigo maligna and superficial spreading type in that it has a relatively long flat phase before it penetrates into the deeper levels of the skin.

Continue Reading