Melanoma: The Basics
Melanoma is a type of skin cancer that forms from melanocytes. Melanocytes are cells in the skin that produce melanin. Melanin is a black or brown pigment (color) seen in the skin, hair, and parts of the eye. Melanoma can occur any place that melanocytes are found, including the skin (nail beds, soles of the feet, scalp), eyes, and mucosal membranes lining the sinuses, gastrointestinal tract, and vagina.
Exposure to ultraviolet radiation from the sun is the leading cause of melanoma. Other risk factors include: fair skin, a history of peeling sunburns, prolonged exposure to ultraviolet light (tanning bed use), multiple moles, older age, and a history of non-melanoma skin cancer (either yourself or a family member).
The best screening test for melanoma is a full skin examination. During routine physicals, your provider may check your skin but it is also important to check your own skin regularly. You will notice any changes early if you do your own checks and are familiar with your skin. These changes can be reported to your provider for further workup.
Moles that cause concern are those that present with the “ABCDE” characteristics.
- Asymmetry - refers to the shape of the mole. One side of the mole not being the same as the other may be of concern.
- Border Irregularity – the border (edges of the mole) should be well-defined. An irregular border appears blurry or uneven.
- Color – multiple colors within a mole or mole whose color has changed is concerning.
- Diameter – Any mole that is larger than the diameter of a pencil eraser may be concerning.
- Evolution – any change in appearance, color, shape, or elevation over time requires additional evaluation.
Signs & Symptoms of Melanoma
Any mole or skin change with the “ABCDE” characteristics. More advanced lesions may be inflamed, oozing, crusting, ulcerated, or bleeding. If a mole goes undetected, the first sign may be a symptom of metastatic spread to other organs.
Diagnosis of Melanoma
When your health care provider suspects melanoma, a biopsy will be performed. Excisional (removal of entire lesion) or incisional (only part of the lesion) biopsy may be used. Both types of biopsies remove the layers beneath the lesion to determine how deep it is. A pathology report will be completed by a dermatopathologist and sent to your provider. A pathology report describes all of the aspects of the melanoma, which helps determine prognosis and treatment. You can request a copy of your report for your records.
To guide treatment, melanoma is staged using the Breslow Depth scale:
- Melanoma in-situ: the melanoma is only in the epidermis.
- Stage I and II: confined to the skin.
- Stage III: spread to the local lymph nodes or surrounding area.
- Stage IV: distant metastasis present.
The TNM system is also used to describe melanoma. This includes:
- Size and location of the tumor.
- Whether cancer cells are found in the lymph nodes.
- Whether cancer cells are found in other areas of the body.
Staging ranges from I (limited disease) to IV (more advanced disease).
Surgery is the first choice of treatment to cure melanoma. A “wide local” excision procedure is done to remove the entire lesion and an area of normal tissue surrounding the lesion. Terms you may find helpful:
- Margins: tissue around a tumor/melanoma lesion.
- Negative Margins: small amount of normal tissue around the entire tumor was removed and contained no cancer cells.
- Positive Margins: melanoma cells are found in the area of “normal tissue” removed. Further surgery is necessary to remove a larger area of normal tissue.
- Another type of surgery used to treat melanoma is the MOHS procedure.
Other types of treatment include:
- Chemotherapy can be used to treat melanoma that can be seen on imaging studies or to prevent recurrence in higher risk melanoma.
- Immunotherapy is a medication that stimulates the immune system, causing it to attack cancer cells.
- Targeted Therapy is the use of medications that target something specific found on the cancer cells. If the melanoma has either a BRAF or MEK mutation, a targeted therapy may be used.
- Isolated Limb Perfusion/Infusion is a procedure in which circulation to the limb where the melanoma is located is cut off temporarily and high doses of chemotherapy and heat are administered to that limb.
- Radiation Therapy, the use of high energy x-rays to kill cancer cells, may be used.
This article is a basic introduction to melanoma. You can learn more about your type of melanoma and treatment by using the links below.
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NCCN Guidelines Version 2.2021 Melanoma. Found at: https://www.nccn.org/professionals/physician_gls/pdf/cutaneous_melanoma.pdf
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