Malignant Melanoma

What Is It?
Malignant melanoma is the most rare but also the most dangerous and invasive form of skin cancer. Whereas squamous cell carcinoma and basal cell carcinoma tend to grow and invade tissues slowly and metastasize rarely, melanoma is a rapidly growing, invasive tumor which has a high propensity to spread to distant tissues.

This tumor is a tumor of melanocytes, the pigment producing cells that are numerous in the bottom layer of the epidermis.

Because it spreads so quickly, it is the most lethal form of skin cancer and can be quite difficult to treat.

What Causes It?
As for other forms of skin cancer, sun exposure is the largest risk factor for developing this cancer. The highest risk is for those with fair skin and light eye and/or hair color. In particular, brief, intense exposure to sun rays (such as with sunbathing) appears to be a particularly important risk.

What Does It Look Like?
Malignant melanoma can arise on any area of skin. However, whereas squamous cell and basal cell most often present on sun exposed areas (head, neck, hands, etc.), melanoma can occur elsewhere. Areas that are exposed during sunbathing (legs, back, buttocks, etc.) are often sites for the tumor to develop.

Melanoma can arise from previously normal appearing skin but can also arise from a pre-existing mole. They can be quite variable in appearance, ranging from a very small dark spot to larger abnormal or "ugly looking" bumps. Characteristics that are worrisome include asymmetry (irregular shapes), irregular or blurred borders with the surrounding skin, uneven color (these are often black or black-blue but may include varying shades of black, brown and tan) and a rapid increase in size. These tumors can also ulcerate, bleed and/or scab in the middle.

Distinguishing these tumors from moles or other dark spots can be difficult, but attention should definitely be paid to lesions that change significantly. A simple skin biopsy can usually make the diagnosis and differentiate melanoma from other lesions of the skin.

What Is The Prognosis?
Malignant melanoma is the most aggressive and potentially lethal form of skin cancer. Unfortunately, the overall prognosis is quite poor. However, this can vary based on several factors. Tumors that are caught very early and are removed fully can have a better prognosis. However, because melanoma spreads so fast, is very invasive into surrounding tissue and rapidly metastasizes to other parts of the body, control of this cancer can be difficult or impossible. In fact, many patients have distant metastases of the tumor even before the primary tumor is diagnosed.

In patients who present with an invasive or widespread cancer, treatment often involves chemotherapy and/or radiation treatments as well as surgical treatments to remove the tumors. Even with this aggressive therapy, melanoma may not be controlled.