What is Melanoma?

The most dangerous form of skin cancer, these cancerous growths develop when unrepaired DNA damage to skin cells (most often caused by ultraviolet radiation from sunshine or tanning beds) triggers mutations (genetic defects) that lead the skin cells to multiply rapidly and form malignant tumors. These tumors originate in the pigment-producing melanocytes in the basal layer of the epidermis. Melanomas often resemble moles; some develop from moles. The majority of melanomas are black or brown, but they can also be skin-colored, pink, red, purple, blue or white. Melanoma is caused mainly by intense, occasional UV exposure (frequently leading to sunburn), especially in those who are genetically predisposed to the disease. Melanoma kills an estimated 9,710 people in the US annually.

If melanoma is recognized and treated early, it is almost always curable, but if it is not, the cancer can advance and spread to other parts of the body, where it becomes hard to treat and can be fatal. While it is not the most common of the skin cancers, it causes the most deaths. The American Cancer Society estimates that at present, more than 120,000 new cases of melanoma in the US are diagnosed in a year. In 2014, an estimated 76,100 of these will be invasive melanomas, with about 43,890 in males and 32,210 in women.

What to look for?

Moles, brown spots and growths on the skin are usually harmless — but not always. Anyone who has more than 100 moles is at greater risk for melanoma. The first signs can appear in one or more atypical moles. That’s why it’s so important to get to know your skin very well and to recognize any changes in the moles on your body. Look for the ABCDE signs of melanoma, and if you see one or more, make an appointment with a physician immediately.

• A – Asymmetry: If you draw a line through this mole, the two halves will not match.
• B – Border: The borders of an early melanoma tend to be uneven. The edges may be scalloped or notched.
• C – Color: Having a variety of colors is another warning signal. A number of different shades of brown, tan or black could appear. A melanoma may also become red, blue or some other color.
• D – Diameter: Melanomas usually are larger in diameter than the size of the eraser on your pencil (1/4 inch or 6 mm), but they may sometimes be smaller when first detected.
• E – Evolving: Any change — in size, shape, color, elevation, or another trait, or any new symptom such as bleeding, itching or crusting — points to danger.

Treatment

The first step in treatment is the removal of the melanoma, and the standard method of doing this is by surgical excision (cutting it out). Surgery has made great advances in the past decade, and much less tissue is removed than was customary in the past. Patients do just as well after the lesser surgery, which is easier to tolerate and produces a smaller scar.

Surgical excision is also called resection, and the borders of the entire area excised are known as the margins.

Outpatient/Office Surgery

In most cases, the surgery for thin melanomas can be done as an outpatient procedure under local anesthesia. Stitches (sutures) remain in place for one to two weeks, and most patients are advised to avoid heavy exercise during this time. Scars are usually small and improve over time.

Discolorations and areas that are depressed or raised following the surgery can be concealed with cosmetics specially formulated to provide camouflage. If the melanoma is larger and requires more extensive surgery, a better cosmetic appearance can be obtained with flaps made from skin near the tumor, or with grafts of skin taken from another part of the body. For grafting, the skin is removed from areas that are normally or easily covered with clothing.

There is now a trend towards performing sentinel node biopsy and tumor removal surgery at the same time, provided the tumor is 1 mm or more thick. When the procedures are combined in this way, the patient is spared an extra visit.

Surgical excision is also called resection, and the borders of the entire area excised are known as the margins. Surgical excision is used to treat all types of skin cancer. At its best – given an experienced surgeon and a small, well-placed tumor – it offers results that are both medically and cosmetically excellent.

The physician begins by outlining the tumor with a marking pen. A “safety margin” of healthy-looking tissue will be included, because it is not possible to determine with the naked eye how far microscopic strands of tumor may have extended. The extended line of excision is drawn, so the skin may be sewn back together.

The physician will administer a local anesthetic, and then cut along the lines that were drawn. The entire procedure takes about thirty minutes for smaller lesions.

Wounds heal rapidly, usually in a week or two. Scarring depends on many factors, including the placement of the tumor and the patient’s care of the wound after the procedure.

The tissue sample will be sent to a lab, to see if any of the “safety margin” has been invaded by skin cancer. If this is the case, it is assumed that the cancer is still present, and additional surgery is required.

Setting the Margins

• In the new approach to surgery, much less of the normal skin around the tumor is removed and the margins, therefore, are much narrower than they ever were before.
• When there is an in situ melanoma, the surgeon excises 0.5-1 centimeter of the normal skin surrounding the tumor and takes off the skin layers
• down to the fat.
• In removing an invasive melanoma that is 1 mm or less in Breslow’s thickness, the margins of surrounding skin are extended to 1 cm and the excision goes through all skin layers and down to the fascia (the layer of tissue covering the muscles).
• If the melanoma is 1.01 to 2 mm thick, a margin of 1-2 cm is taken.
• If the melanoma is 2.01 mm thick or greater, a margin of 2 cm is taken.
• These margins all fall within the range of what is called “narrow” excision. When you consider that until recently, margins of 3 to 5 cm (wide excision) were standard, even for comparatively thin tumors, you can see how dramatically surgery has changed for the better. Physicians now know that even when melanomas have reached a thickness of 4 mm or more, increasing the margins beyond 2 cm does not increase survival.

Sentinal Lymph Node Biopsy

• A sentinel lymph node biopsy is a procedure that helps the doctor find out whether melanoma has spread to the lymph nodes.
• If melanoma is found during a sentinel lymph node biopsy, the doctor should remove more lymph nodes.
• Talk with your doctor about what kind of procedure is needed to evaluate and treat your melanoma and what the results will mean.

Background

Melanoma is a type of cancer that starts in color-producing cells of the skin called melanocytes. Often, but not always, melanoma develops from an existing mole. Melanoma can grow deep into the inner layers of skin and spread to the lymph nodes (tiny, bean-shaped organs that help fight infection) and other parts of the body. Treatment for melanoma is determined by the thickness (how deep the tumor has grown into the layers of the skin) of the primary tumor and whether it has spread. This is also called the stage of the cancer. Whether melanoma has spread to the lymph nodes is one of the most important factors in determining a patient’s prognosis (chance of recovery).

A sentinel lymph node biopsy (also called sentinel node biopsy or SNB) is a procedure that helps the doctor find out whether the cancer has spread to the lymph nodes. When cancer spreads from the place it started to the lymph nodes, it travels through the lymphatic system. A sentinel lymph node is the first node into which the lymphatic system drains. Because melanoma can start anywhere on the skin, the location of the sentinel lymph nodes will be different depending on where the cancer started. To find the sentinel lymph node, a harmless radioactive substance is injected as close as possible to where the melanoma started. The substance is followed to the sentinel lymph node. Then, the doctor removes one or a few of these lymph nodes to check for melanoma cells, leaving behind most of the other lymph nodes in that area.

If the biopsy results show that the cancer has not spread to the sentinel lymph node, then no additional lymph node surgery is needed. However, if melanoma is found in the sentinel lymph nodes, a lymph node dissection is usually recommended. A lymph node dissection is the surgical removal of the remaining lymph nodes in that area. The risks of a lymph node dissection vary depending on the number of lymph nodes removed during the procedure.

Recommendations

• SNB is recommended for patients with a melanoma that developed on any part of the surface of the skin and is 1 millimeter (mm) to 4 mm thick.
• SNB may be recommended to help stage and determine treatment for a melanoma that is thicker than 4 mm.
• SNB is not recommended for most patients with a thin melanoma (less than 1 mm thick), although it may be considered if the melanoma has a high risk of spreading. It is not yet certain which patients with a thin melanoma have a higher risk of the disease spreading to the lymph nodes. However, some high-risk features of melanoma include ulceration (the outer layer of skin over the melanoma is missing when viewed under a microscope) or a high mitotic rate (more cells that are dividing; a sign that the cancer may be growing rapidly).

A lymph node dissection is recommended for all patients when melanoma is found in the sentinel lymph nodes.

What This Means for Patients

For many patients with a melanoma thicker than 1 mm, SNB is a useful way to find out whether the cancer has spread from where it began. It helps your doctor plan treatment and can help you understand your prognosis. There are few side effects from the procedure, but a patient may experience infection, seroma (fluid build-up) near the surgical area, numbness, and re-opening of the surgical area. Rarely, lymphedema (build-up of lymph fluid) may occur. However, this side effect is more common for patients who have had a lymph node dissection.

If melanoma is found in the sentinel lymph nodes, a lymph node dissection to remove the remaining lymph nodes in that area allows the doctors to find out whether the cancer has spread and remove any additional lymph nodes that may contain melanoma. A patient may take longer to recover after a lymph node dissection and has a higher risk of side effects. For example, a patient who has had a lymph node dissection in the armpit or groin has a higher risk of lymphedema. However, the results of a lymph node dissection help your doctor make sure you get the appropriate treatment for your stage of melanoma. Talk with your doctor about the tests needed to diagnose melanoma and determine the stage, and how these results affect your treatment options.