Superficial Spreading Melanoma Stage Unspecified

Superficial spreading melanoma is the most common form of melanoma, accounting for approximately 70% of all cases. This type of skin cancer typically grows slowly along the surface of the skin for months or even years before potentially spreading deeper.

C43.9
2C30.0

Table of contents

• What Is Superficial Spreading Melanoma?
• Who Gets Superficial Spreading Melanoma?
• What Causes This Type of Melanoma?
• How Does It Look and Where Does It Appear?
• How Is It Diagnosed?
• Treatment Options
• Prevention

What Is Superficial Spreading Melanoma?

Superficial spreading melanoma is a type of skin cancer that develops from melanocytes, which are cells in the skin that produce pigment (the substance that gives skin its color). These pigment cells are located along the bottom layer of the outermost part of your skin, called the epidermis^[2].

The name “superficial spreading” describes how this cancer typically grows. Instead of immediately growing downward into deeper layers of skin, it tends to spread outward along the surface of the skin. This growth pattern is called the radial growth phase, and the cancer cells may stay within the top layer of skin for an extended period—from months to several years or even decades^[2].

During this early phase, when cancer cells remain only in the outermost skin layer without crossing into deeper tissue, doctors call it melanoma in situ^[6]. However, an unknown number of these melanomas eventually become invasive, meaning the cancer cells break through into the deeper skin layer called the dermis. When this happens, a faster-growing tumor can develop and spread more deeply into the skin^[2].

Who Gets Superficial Spreading Melanoma?

Superficial spreading melanoma is the most common type of melanoma. It accounts for about 70 percent of all melanoma cases diagnosed^[4]. This cancer affects men and women equally^[2].

While this type of melanoma can occur at any adult age, only about 15 percent of cases develop in people younger than 40 years old, and it is quite rare in people under age 20^[2].

Superficial spreading melanoma almost always occurs in people with white skin. It is more common in people with very fair skin (those who burn easily and rarely tan), but it can also develop in people who tan more easily. This cancer is rare in people with brown or black skin^[2].

Certain factors increase the risk of developing superficial spreading melanoma. People at higher risk include those who have^[2]:

• More than 100 moles (colored spots on the skin)
• More than five unusual or abnormal-looking moles
• A strong family history, with two or more close relatives who have had melanoma
• Fair skin that burns easily
• A history of severe sunburns that caused blistering

Other factors that somewhat increase risk include having blue or green eyes, red or blonde hair, working indoors but spending recreational time outdoors, and having visible sun damage on the skin^[2].

What Causes This Type of Melanoma?

Superficial spreading melanoma develops when pigment-producing cells in the skin become abnormal and grow out of control. Most cases—about 70 to 75 percent—appear on skin that previously looked normal. About 25 percent develop within an existing mole, which could be a common mole, an unusual-looking mole, or a mole that was present since birth^[2].

Scientists do not fully understand what triggers these skin cells to become cancerous. However, they have identified certain gene mutations (changes in the cell’s genetic material) in many superficial spreading melanomas. One specific mutation called BRAFV600E is frequently found in these cancers, and these genetic changes may evolve as the disease progresses^[2].

Exposure to ultraviolet (UV) radiation—the invisible rays in sunlight and from artificial sources like tanning beds—plays a major role in causing this cancer. UV radiation damages the DNA inside skin cells, affecting genes that control how cells grow and divide. This damage also weakens the skin’s immune defenses, allowing abnormal cells to multiply unchecked^[2][3].

The most significant UV-related risk comes from intense, intermittent sun exposure—particularly sunburns, especially during childhood and young adulthood^[3][5].

How Does It Look and Where Does It Appear?

Superficial spreading melanoma tends to develop on areas of the body that receive intense sun exposure occasionally rather than constantly. In men, it most commonly appears on the trunk (the chest, back, or abdomen), affecting about 40 percent of male patients. In women, the legs are the most common site, also accounting for about 40 percent of cases in females^[2].

When this melanoma first appears, it may look like a mole, freckle, or age spot. As time passes, it becomes more distinctive, typically growing over months to years before being recognized as abnormal^[2].

You can recognize potentially dangerous skin changes using the ABCDE rule^[3]:

• A is for Asymmetry: One half of the spot looks different from the other half
• B is for Border: The edges are uneven, jagged, or poorly defined
• C is for Color: The spot contains multiple colors or shades—it may include various tones of brown, black, gray, red, white, pink, or blue
• D is for Diameter: The spot is larger than 6 millimeters across (about the size of a pencil eraser), though melanomas can sometimes be smaller
• E is for Evolving: The spot is new or has changed in size, shape, or color

Superficial spreading melanoma may appear as a slowly growing or changing flat patch of discolored skin. It can be raised or flat and usually has an irregular shape and borders. The spot may be itchy in some cases^[4].

When diagnosed, these melanomas typically measure about 20 millimeters (about three-quarters of an inch) across^[14].

How Is It Diagnosed?

If you notice an unusual spot on your skin or a mole that looks different from your other moles, you should see a doctor, preferably a dermatologist (a doctor who specializes in skin conditions). The doctor will examine your skin carefully to look for signs that could indicate melanoma^[3].

To confirm whether a suspicious spot is cancer, the doctor will perform a biopsy—a procedure to remove a sample of tissue for testing in a laboratory. There are different types of biopsy procedures. One common method is the punch biopsy, which uses a circular blade pressed into the skin to remove the suspicious area. Another technique is the excisional biopsy, which uses a surgical blade to cut away the entire growth along with some surrounding healthy tissue^[11].

Most often, doctors recommend removing the entire suspicious growth when possible^[11].

If the biopsy confirms melanoma, additional tests may be needed to determine whether the cancer has spread. These tests help doctors assign a stage to the cancer, which describes how advanced it is. Determining the stage involves checking the thickness of the melanoma (thicker melanomas are generally more serious) and looking for signs that cancer cells have spread to nearby lymph nodes or other parts of the body^[11].

Treatment Options

Surgery is the main treatment for superficial spreading melanoma, especially when it is found early^[9].

The standard surgical approach involves removing the melanoma along with a margin of healthy-looking skin around it. This helps ensure that any cancer cells that may have spread slightly beyond the visible tumor are also removed^[9].

If the melanoma has spread to nearby lymph glands (small bean-shaped organs that are part of the body’s immune system), surgery may be needed to remove these glands^[13].

When a large area of skin must be removed, surgeons may perform a skin graft, taking skin from another part of the body to cover the area where the melanoma was^[13].

For melanomas that cannot be completely removed with surgery or that have spread to other areas, additional treatments may be used^[13]:

Radiotherapy (also called radiation therapy) uses high-energy rays to kill cancer cells. It is sometimes used to reduce the size of large melanomas or to help control symptoms^[13].

Immunotherapy uses medicines that help your body’s own immune system recognize and destroy cancer cells. These treatments are sometimes used for melanomas that cannot be treated with surgery or that have spread^[13].

Targeted medicines work by blocking specific changes in cancer cells that help them grow. Before starting these treatments, doctors usually test a sample of the melanoma to check for particular genetic changes that would make targeted medicines likely to work^[13].

Chemotherapy uses medicines to kill rapidly dividing cancer cells. It does not work as well for melanoma as some other treatments, but may be used when other options are not suitable^[13].

After treatment, you will need regular follow-up visits with your doctor. The frequency and types of check-ups will depend on the stage of your melanoma^[13].

Prevention

The most important step in preventing superficial spreading melanoma is protecting your skin from UV radiation^[3].

Key prevention strategies include:

• Avoiding intense sun exposure, especially during midday hours when the sun’s rays are strongest
• Wearing protective clothing, including wide-brimmed hats and long-sleeved shirts when outdoors
• Using sunscreen with a high sun protection factor (SPF) on exposed skin
• Avoiding tanning beds and sun lamps entirely
• Being extra careful to prevent sunburns, particularly in children

Regular skin self-examinations are also important. Check your entire body regularly for any new spots or changes in existing moles. If you notice anything unusual, see a doctor promptly. When melanoma is caught in its earliest stages, it is highly curable—the five-year survival rate exceeds 98 percent for melanoma that has not spread^[3].

If you have risk factors such as many moles, unusual-looking moles, very fair skin, or a family history of melanoma, talk to your doctor about how often you should have professional skin examinations^[2].