This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on May 27, 2022.
The most common melanomas are cutaneous, which develop on the skin, particularly in areas exposed to the sun. In men, the most common sites for melanoma are the chest or back. In women, the legs are affected most frequently. However, melanomas are also commonly found on the neck or face, and in areas not exposed to the sun, such as the groin or under the fingernails.
Superficial spreading melanoma is the most common type of melanoma. This slow growing melanoma may develop for several years along the outer layer of the skin. Superficial spreading melanomas may be elevated and have irregular borders. They may be brown with black or pink edges. Seventy percent of cases diagnosed are superficial spreading melanomas, according to the National Cancer Institute (NCI).
After first appearing on the surface of the skin, nodular melanoma may quickly grow into deeper layers of the skin. This form of the disease may appear as a bump or a growth. Nodular melanomas account for 15 percent of all cases.
Acral-lentiginous melanoma is most common among people with darker skin. This type of melanoma represents up to 70 percent of melanomas in African Americans and 46 percent of all cases in Asians, according to the NCI. Acral-lentiginous melanoma may be found on the palms of the hands, soles of the feet and under the nails.
When melanoma forms under the nails, it’s known as subungual melanoma, a subtype of acral-lentiginous melanoma. Patients with subungual melanoma may notice streaks of brown or black discolorations under their nails, or they may experience thick, frayed or splitting of the nail. This type of cancer represents about 0.7 percent to 3.5 percent of all malignant melanomas globally. Most cases of subungual melanoma are seen in the thumb or big toe.
Lentigo maligna melanomas are most often found in adults on the arms, legs, face, neck and other areas exposed to the sun. The risk of this type of melanoma may increase with age because of prolonged sun exposure. Lentingo maligna, a slow-growing melanoma, is the most common form of melanoma in Hawaii, according to the Skin Cancer Foundation.
These two similar and rare forms of melanoma may be aggressive and difficult to diagnose. Amelanotic melanoma may be difficult to spot because of its lack of pigment. Desmoplastic melanoma may be found on the head and neck of elderly patients.
Ocular melanoma develops in the melanocytes that give eyes their color. They account for about 3 percent of all melanoma cases, according to the Ocular Melanoma Foundation. More than 2,000 cases of ocular melanoma are diagnosed each year. Types of ocular melanoma include choroidal melanoma, iris melanoma and uveal melanoma.
Mucosal melanoma is a rare but aggressive disease usually diagnosed in advanced stages. Unlike most melanomas, which start in the skin, mucosal melanoma starts in the moist membranes that line the inside of the body, including the digestive tract.
Once melanoma spreads, or metastasizes, the disease is known as metastatic melanoma. This type of melanoma may typically occur during stage 3 or stage 4. Common sites for metastases include the lymph nodes, lungs, liver, bones and brain.
Next topic: What is metastatic melanoma?