Melanoma

What is Melanoma?

Melanoma is a type of cancer that develops in the melanocytes, the cells responsible for producing melanin, the pigment that gives skin its color. It is considered the most serious type of skin cancer because it can spread to other parts of the body if not detected and treated early.

There are several types of melanoma, each with distinct characteristics. Here are the main types:

  • Superficial Spreading Melanoma
    • Description: The most common type of melanoma, accounting for about 70% of cases.
    • Appearance: Often starts as a flat or slightly raised discolored patch with irregular borders and varies in color (brown, black, pink, red, white, or blue).
    • Growth Pattern: Tends to grow horizontally across the top layer of the skin before penetrating deeper.
  • Nodular Melanoma
    • Description: The second most common type, making up about 15-20% of melanomas.
    • Appearance: Usually appears as a raised bump that's dark blackish-blue or bluish-red, though some can be skin-colored.
    • Growth Pattern: Grows more quickly in depth than in width, making it more aggressive.
  • Lentigo Maligna Melanoma
    • Description: Accounts for about 5-10% of melanomas, more common in older adults.
    • Appearance: Typically appears as a large, flat, brownish patch with darker spots, often on sun-damaged skin of the face, ears, arms, or upper trunk.
    • Growth Pattern: Grows slowly over many years, initially in the top layer of skin (in situ) before becoming invasive.
  • Acral Lentiginous Melanoma
    • Description: A rare form of melanoma, more common in people with darker skin tones.
    • Appearance: Usually appears on the palms, soles, or under the nails as a dark spot or streak.
    • Growth Pattern: Tends to spread superficially before penetrating deeper layers of the skin.
  • Amelanotic Melanoma
    • Description: A less common type of melanoma that lacks the dark pigment melanin.
    • Appearance: Can be colorless or pinkish, reddish, or light brown, making it harder to diagnose.
    • Growth Pattern: Similar to other melanomas but can be mistaken for other skin conditions due to its lack of color.
  • Desmoplastic Melanoma
    • Description: A rare form of melanoma that often occurs on sun-exposed areas of the skin.
    • Appearance: Presents as a firm, flesh-colored or slightly pigmented nodule.
    • Growth Pattern: Known for a high tendency to recur and can be more challenging to treat due to its fibrous nature.
  • Mucosal Melanoma
    • Description: An uncommon type of melanoma occurring in the mucous membranes of the body, such as the nasal passages, throat, anus, or vagina.
    • Appearance: Symptoms vary depending on the location and can include lumps, sores, or bleeding.
    • Growth Pattern: Often diagnosed at a later stage due to the difficulty in detecting it early.
  • Ocular Melanoma
    • Description: Melanoma that develops in the eye, also known as uveal melanoma.
    • Appearance: Symptoms may include visual changes, dark spots on the iris, or a visible mass in the eye.
    • Growth Pattern: Can spread to other parts of the body if not treated promptly.

Risk Factors

  • Ultraviolet (UV) Radiation Exposure
    • Sun Exposure: Prolonged exposure to UV radiation from the sun is a significant risk factor. Sunburns, especially blistering sunburns during childhood, can increase the risk.
    • Tanning Beds: Use of indoor tanning beds significantly increases the risk of melanoma, especially in young people.
  • Skin Type and Color
    • Fair Skin: People with fair skin, light hair (blonde or red), and light-colored eyes (blue or green) are at higher risk. Fair-skinned individuals have less melanin, which provides some protection against UV radiation.
    • Freckles and Moles: Having a large number of moles or atypical moles increases the risk of melanoma. Freckles and skin that burns easily also contribute to a higher risk.
  • Genetic Factors
    • Family History: A family history of melanoma increases the risk, suggesting a genetic predisposition.
    • Genetic Mutations: Certain genetic mutations, such as those in the CDKN2A and BRAF genes, are linked to a higher risk of melanoma.
  • Personal History of Skin Cancer
    • Previous Melanoma: Individuals who have previously had melanoma are at an increased risk of developing a second melanoma.
    • Other Skin Cancers: Having other types of skin cancer, such as basal cell carcinoma or squamous cell carcinoma, can increase the risk of melanoma. *
  • Immune System Suppression
    • Immunosuppressive Medications: People taking medications that suppress the immune system, such as those used after organ transplants, are at higher risk.
    • Medical Conditions: Conditions that weaken the immune system, such as HIV/AIDS, can increase the risk of melanoma.
  • Age and Gender
    • Age: The risk of melanoma increases with age, although it can also affect younger individuals.
    • Gender: Before age 50, melanoma is more common in women than in men. After age 50, the incidence is higher in men.
  • Environmental Factors
    • Geographic Location: Living in areas with high levels of UV radiation, such as near the equator or at high altitudes, increases the risk.
    • Occupational Exposure: Jobs that involve prolonged outdoor exposure can increase the risk.
  • Other Factors
    • Radiation Therapy: Previous radiation treatment for other conditions can increase the risk of developing melanoma.
    • Certain Chemicals: Exposure to certain chemicals, such as arsenic, can increase the risk.

Individuals with multiple risk factors or who notice unusual skin lesions should seek medical evaluation by a GW Cancer Center cutaneous oncologist. Early detection and appropriate treatment are crucial in managing melanoma.