What Are the Types of Melanoma?

Superficial spreading melanoma

Superficial spreading melanoma (SSM) is the most common type of cutaneous (skin) melanoma. It makes up about 70% of all cutaneous melanoma diagnoses.

SSM starts on the surface of your skin in a preexisting mole or as a new lesion. It first spreads outward and eventually invades deeper skin layers. Like all melanomas, it can begin anywhere but is most common on the torso of males and the legs of females.

SSM is typically a flat or slightly raised spot on your skin that can have:

• an asymmetrical shape
• an irregular or smudgy border
• variable color that may include light or dark brown, black, blue, gray, pink, or red
• a different appearance than other moles on your body
• noticeable changes over time, such as growing larger

Risk factors for SSM include:

• increasing age
• exposure to UV radiation (especially a history of severe sunburns)
• personal or family history of melanoma
• light skin tone
• the presence of many moles or multiple atypical moles

Nodular melanoma

Nodular melanoma (NM) makes up about 20% of all cutaneous melanomas. It typically starts as a raised bump, or nodule, on your skin.

NM can be black, brown, or red. Alternatively, in many cases, it can be similar to the natural color of your skin and will therefore be harder to identify. It’s typically found on your head or neck.

NM is more common in males and older adults. It grows rapidly and deeper into your skin than some other types of melanoma. Because of this, diagnosis often occurs at a later stage, leading to a less favorable outlook.

Lentigo maligna melanoma

Lentigo maligna melanoma (LMM) makes up 4–15% of all cutaneous melanomas. It starts from a precancerous condition that affects the top layer of skin and becomes LMM when it spreads into deeper skin layers.

LMM typically affects older adults and starts in areas that have a lot of sun exposure, particularly the head and neck. For this reason, cumulative sun exposure over your lifetime is a major risk factor. Anyone can get LMM, but it’s more common in females.

This type of melanoma starts as a tan or brown spot with an abnormal shape. It tends to grow more slowly than other types of melanoma and, as a result, typically has a better outlook.

Acral lentiginous melanoma

Acral lentiginous melanoma (ALM) starts on areas of your body that don’t get much sun exposure, such as:

• the palms of your hands
• the bottoms of your feet
• under your fingernails or toenails

Experts do not believe that sun exposure contributes to ALM. In this way, it differs from many other types of melanoma.

ALM is rare, making up 1–3% of cutaneous melanomas. Still, it’s quite aggressive and can quickly invade deeper layers of skin.

This type of melanoma also accounts for a large proportion of melanomas diagnosed in skin of color. In fact, it makes up 40–60% of melanoma diagnoses in African American and Asian people.

ALM is typically light to dark brown in color. It may become ulcerated as it progresses.

Rare cutaneous melanomas

The following sections discuss rarer forms of cutaneous melanoma.

Desmoplastic melanoma

Desmoplastic melanoma makes up less than 4% of cutaneous melanomas. It can look like scar tissue but may also resemble other types of cancerous and noncancerous skin lesions. About 60% of these melanomas are unpigmented.

It’s often found on areas of skin with lots of sun exposure, especially the head and neck. Other common locations are the torso, arms, and legs. Because this type resembles other skin lesions and can lack pigment, it’s difficult to diagnose.

Amelanotic melanoma

Like desmoplastic melanoma, amelanotic melanoma lacks pigment. Therefore, it can be difficult to diagnose in its early stages, leading to a less favorable outlook.

This type of melanoma makes up 2–8% of all cutaneous melanomas. People who develop this type of melanoma are often older. It’s typically found on sun-exposed areas such as the head, neck, torso, and legs.

Nevoid melanoma

Nevoid melanomas are very rare, making up less than 1% of all melanomas. They can be difficult to diagnose because they often resemble benign moles.

Spitzoid melanoma

Spitzoid melanoma is a type of melanoma similar to a benign skin lesion called a spitz nevus. This type makes up less than 2% of all cutaneous melanomas.

These melanomas typically appear on the head, arms, or legs. They are often round and have a uniform color of brown, black, or blue. They grow quickly and often spread to regional lymph nodes, but distant spread is rare.

Eye melanoma

Eye melanoma is rare. The American Cancer Society estimates that U.S. doctors will diagnose 3,320 new cases of eye cancer, which will mainly be eye melanoma, in 2024.

Eye melanoma typically starts in the middle layer of the eye, called the uvea. In rare cases, it can develop in the conjunctiva, which is the tissue covering the white of your eye. Symptoms of eye melanoma can include:

• a dark spot on your eye
• blurry vision
• a blind spot in your field of vision
• a feeling like you’re seeing flashing lights
• a noticeable change in the shape of your pupil
• sun sensitivity

Exposure to sunlight is a risk factor for eye melanoma. Other risk factors include:

• lighter skin tone or lighter-colored eyes
• a preexisting mole on your eye
• older age

Mucosal melanoma

Mucosal melanoma starts in mucus membranes such as your:

• sinuses
• mouth
• throat
• genitals
• urinary tract
• rectum and anus

Symptoms vary based on location. For example, in your sinuses, it may cause persistent runny nose, nosebleeds, or nasal obstruction. In your rectum or anus, it may lead to constipation, pain, and rectal bleeding.

Mucosal melanoma is a very rare type of melanoma, making up 2% or less of all melanomas. However, it’s an aggressive type that often has an unfavorable outlook.

Mucosal melanoma differs from many other melanomas in that exposure to UV radiation isn’t a risk factor for it. Risk factors for this type of melanoma are not well understood.

Melanoma of unknown primary

Most melanomas have a known site where the cancer started, such as your skin or eye. However, 3.2% of melanomas are diagnosed at a distant site with no identifiable primary site. This is called melanoma of unknown primary (MUP).

MUP is most commonly found in lymph nodes. It can also be present in subcutaneous tissue or in internal organs such as your intestines or kidneys. The symptoms of MUP can vary based on the area affected.

Generally, MUP tends to have a better outlook than melanomas of the same stage that have known primary sites.

Frequently asked questions

Which type of melanoma is the most aggressive?

Of the four main subtypes of cutaneous melanoma, NM is the most aggressive, meaning that it grows and spreads quickly. Although NM is less common than SSM, experts estimate that NM accounts for 40% of all melanoma-related deaths.

Which types of melanoma have a poor prognosis?

More aggressive types of cutaneous melanoma, such as NM and ALM, tend to have an unfavorable outlook. Mucosal melanoma also has a less favorable outlook than cutaneous melanoma.

What types of melanoma have a high survival rate?

One small 2017 study found that, of the main subtypes of cutaneous melanoma, LMM and SSM had the best outlook.

Takeaway

Most melanomas are cutaneous (skin) melanoma. In rare cases, melanoma can start in your eye or mucus membranes or be found in distant areas with no known primary site.

The symptoms, treatment, and outlook can vary by melanoma type. Because the outlook for most cancers is often better when they’re found early, it’s vital to see a doctor if you have any concerning symptoms, especially suspicious skin lesions.