Melanoma is an aggressive type of skin cancer and represents only 5% of all cutaneous malignancies. These originate in melanocytes, which produce skin pigment, and are at risk for spreading to lymph nodes and other organs. Melanoma may form on normal skin, or develop in a preexisting mole. Rarely, melanomas appear in the mouth, iris of the eye, or retina at the back of the eye. They may be found during dental or eye examinations. Although very rare, melanoma can also develop in the vagina, esophagus, anus, urinary tract, and small intestine. The vast majority of melanomas, however, are seen in sun-exposed areas of the skin. There are a number of different risk factors for melanoma, including sun exposure and family history.
You are more likely to develop melanoma if you:
- Have fair skin, blue or green eyes, or red or blond hair
- Live in sunny climates or at high altitudes
- Spent a lot of time in high levels of strong sunlight, because of a job or other activities
- Have had one or more blistering sunburns during childhood
- Use tanning devices
Other risk Factors include:
- Close relatives with a history of melanoma
- Certain types of moles (atypical dysplastic) or multiple birthmarks
- Weakened immune system due to disease or medication
A mole, sore, lump, or growth on the skin can be a sign of melanoma or other skin cancer. A sore or growth that bleeds, or changes in skin coloring may also be a sign of skin cancer.
The ABCDE system can help you remember possible symptoms of melanoma:
- Asymmetry: One half of the abnormal area is different from the other half.
- Border: Melanoma lesions usually have irregular borders that are difficult to define.
- Color: Color changes from one area to another, with shades of tan, brown, or black, and sometimes white, red, or blue. A mixture of colors may appear within one sore.
- Diameter: The spot is usually (but not always) larger than 6 mm in diameter — about the size of a pencil eraser.
- Evolution: The mole is changing in appearance.
The key to successfully treating melanoma is recognizing symptoms early. You might not notice a small spot if you don’t look carefully. Have yearly body checks by a dermatologist, and examine your skin once a month. Use a hand mirror to check hard-to-see places. Call your doctor if you notice anything unusual.
There are four major types of melanoma:
Superficial spreading melanoma is the most common type. It is usually flat and irregular in shape and color, with different shades of black and brown. It is most common in Caucasians.
Nodular melanoma usually starts as a raised area that is dark blackish-blue or bluish-red. However, some do not have any color.
Lentigo maligna melanoma usually occurs in the elderly. It is most common in sun damaged skin on the face, neck, and arms. The abnormal skin areas are usually large, flat, and tan with areas of brown.
Acral lentiginous melanoma is the least common form. It usually occurs on the palms, soles, or under the nails and is more common in African Americans.
Evaluation & Treatment
While melanoma is a particularly aggressive form of cancer, it is treatable when caught early. Your doctor will check your skin and look at the size, shape, color, and texture of any suspicious areas. If your doctor thinks you might have skin cancer or a melanoma, a biopsy will be performed. This will remove all, or part, of the growth. If the biopsy confirms melanoma, a much more aggressive operation will be necessary.
Melanomas are staged based on several factors, including thickness, microscopic features, lymph node involvement, and spread to distant areas. The staging of your melanoma will be reviewed in detail at your consultation, and will dictate what type and extent of treatment you will require.
Many pathology reports will mention a “Clark’s level,” which is often misunderstood as the stage of the melanoma. Please be aware that Clark’s level is no longer used to stage melanoma and will not be used to determine your prognosis or treatment.
All melanomas require a Wide Local Excision. Many will also require a sampling of the regional lymph nodes, called a Sentinel Lymph Node Biopsy, during the same operation.
Wide Local Excision
Wide local excision is the term used for removing the melanoma with a margin of normal tissue around it to minimize the chance of it recurring in the same area. The length of the margin is based on the thickness of your melanoma and its location, and can vary from 5 mm to 2 cm. A full thickness excision is performed extending all the way down through the underlying fatty tissue to the bone or muscle, whichever is most superficial. This tissue is typically removed in the shape of an ellipse, or an elongated football shape. This allows us to close your skin in a straight line, which is more appealing cosmetically. The stitches used to close a wide local excision stay in about 1-3 weeks and will be removed in our office at your follow up appointment. Some melanomas on the face, scalp or other locations may require a skin graft, or a specialized rotation flap closure by a plastic surgeon to close the defect after removal.
Sentinel Lymph Node Biopsy
Based on the stage of your melanoma, we may recommend a sentinel lymph node biopsy. This is a procedure performed in the operating room at the same time as your wide local excision. The purpose of a sentinel lymph node biopsy is to sample the lymph nodes that are at greatest risk for spread, or metastasis, of the melanoma. The first step is a procedure called a lymphoscintigraphy, which involves an injection of a radioactive protein around the melanoma in the Nuclear Medicine department. The protein travels through the lymphatic channels and settles into the lymph nodes that drain the area of your skin where the melanoma is situated. A series of x-rays is performed which helps us identify the location of the lymph nodes that need to be removed. Dr. Davidson will meet with you in the pre operative holding area and review the results of the lymphoscintigraphy with you prior to your surgery. Following your wide local excision, the sentinel lymph nodes are accessed through a small incision and sent to the pathologist for review under the microscope. The results will be available in about 7-10 business days and will either be called to you, or discussed at your post operative visit. The operative procedure takes about 60-90 minutes to perform and no overnight stay is required.