Melanoma is a malignant (cancerous) tumor that is usually found on the skin but can also manifest in the eyes, ears, gastrointestinal tract, leptomeninges and mucous membranes. It is one of three main types of skin cancer; the other two being squamous cell carcinoma and basal cell carcinoma. Melanoma accounts for about 4% of skin cancer cases and about 79% of skin cancer deaths. With early detection and treatment, the five-year survival rate is over 99%. If melanoma spreads to the local lymph nodes, the five-year relative survival rate drops to 62% percent, but about 84% of melanoma cases are detected at a localized stage. Melanoma occurrence increases with age, but is also one of the most common cancers in those ages 25 to 29.
Melanoma originates in the melanin producing melanocytes cells. Melanin gives skin its pigmentation and protects the deeper layers of skin from dangerous ultraviolet rays. Therefore, the more exposure which melanocytes have to sunlight and other forms of ultraviolet light, the more at risk they are of growing abnormally and becoming cancerous melanoma tumors.
The American Academy of Dermatology developed an “ABCDE” guide to identifying melanoma: Asymmetrical (irregularly shaped moles); Border (moles with irregular, notched or scalloped borders); Color (growths that have many colors or uneven distribution of color); Diameter (new growth in a mole larger than about 1/4 inch); Evolving (moles that grow in size or change in color or shape, or develop new signs and symptoms, such as itchiness, scaliness, spreading of pigment beyond the mole, oozing or bleeding).
Five types of melanoma include:
Superficial Spreading Melanoma (SSM)
Superficial spreading melanoma (SSM) is a cutaneous (skin) melanoma that accounts for 70-80% of melanoma cases. SSM usually occurs in previous sunburns and often begins in pre-existing moles. Usually 1-2 centimeters wide, SSM may be raised and/or have an irregular shape and is usually brown, black or tan colored.
Nodular melanoma accounts for 10% of all cutaneous melanoma cases. This type of melanoma usually develops on the trunk and appears as a black-blue, gray, dark brown, pink or skin-colored smooth nodule. Nodular melanoma metastasizes rapidly and often has a poor prognosis.
Lentigo maligna Melanoma
Lentigo maligna melanoma accounts for 5% of melanoma cases. This type of cutaneous melanoma grows slowly and occurs in areas of profound sun exposure as opposed to moles. The tumor is usually flat, deep tan, brown or black colored and has an irregular shape of greater than one centimeter in width.
Acral Lentiginous Melanoma
Acral Lentiginous melanoma occurs in 2-8% of melanomas in Caucasians and 35-90% in African Americans and Hispanics. Found in the palms, soles of feet, oral mucosa and nail beds (areas of the body without hair and that do not receive heavy sun exposure), this tumor grows and spreads rapidly and has a poor prognosis.
Subungual melanoma occurs under the nail bed, forming a dark colored strip that runs down the nail. This melanoma usually occurs in dark-skinned people, accounting for 1% of melanoma cases in Caucasians. The five-year survival rate varies between16-87%.
Disclaimer: This article represents our best efforts but is in no way meant to replace the critical dialogue and recommendations of a healthcare professional. If you believe that you, or someone you know suffers from the conditions described here, see your healthcare provider. Do not attempt to treat/diagnose yourself or anyone else without proper medical supervision.