When you think of melanoma, you may picture a mole that’s grown and changed over time. However, there are several types of melanoma, and each one looks different. Melanoma can show up anywhere on the body, not only where you already have moles. Sometimes, it emerges as a new, odd spot or a part of the skin that doesn’t heal properly. Melanoma also can appear as patches, bumps, or even marks on your nails. Did you know that melanoma can also develop in the eye? This condition is known as ocular melanoma.

This article discusses the four most common types of melanoma, along with five less common types to be aware of. If you find a new or concerning spot on your skin, talk to your doctor or dermatologist (skin specialist) right away. Diagnosing melanoma early and starting treatment is important because it can spread to other parts of the body.

How Does Melanoma Develop?

Your skin contains cells known as melanocytes. Melanocytes make the pigment melanin that gives your skin its color. Melanoma skin cancer develops when genetic changes in melanocytes cause them to grow and divide uncontrollably, creating tumors.

Melanoma is a different type of skin cancer than basal cell carcinoma or squamous cell carcinoma. These more common types of skin cancer don’t involve the melanocytes.

Most Common Types of Melanoma

Melanoma usually develops in the skin, but it can develop in other tissues. Skin melanoma, also called cutaneous melanoma, is most common. It usually develops on areas of skin exposed to the sun. There are four main types of skin melanoma. Each type is defined by where it forms on the body and how it grows.

1. Superficial Spreading Melanoma

Superficial spreading melanoma is the most common type of skin melanoma. Studies show that 70 percent of people diagnosed with melanoma have this type.

Superficial spreading melanoma starts by growing outward in a flat layer on top of the skin. Eventually, it can begin growing deeper into the skin as well.

If you have a superficial spreading melanoma, you may notice a flat or slightly elevated mole or lesion that’s brown, black, blue, gray, red, or white — depending on your skin tone. Most superficial spreading melanomas develop from an existing mole (nevus-associated melanoma), and some form from new moles (de novo melanoma).

Anyone at any age can develop superficial spreading melanoma, but it’s usually found in people under the age of 40. The most common places for this type of melanoma to develop include the arms, legs, and trunk (middle of the body). Men tend to develop superficial spreading melanomas on their backs, according to the Canadian Cancer Society, and women tend to get them on their legs.

2. Nodular Melanoma

The second most common type of cutaneous melanoma is nodular melanoma — found in 15 percent to 30 percent of cases. Nodular melanomas tend to grow faster and deeper into the skin compared to other types. This melanoma is considered to be more aggressive, and people are usually first diagnosed with a later stage of nodular melanoma compared to superficial spreading melanoma.

Nodular melanomas form round, raised bumps or nodules on the skin’s surface. They’re usually black or dark brown. However, around 5 percent of nodular melanomas are red, pink, or even the same color as your skin (amelanotic melanomas). This means they’re harder to diagnose, and they may go undetected for some time.

Nodular melanomas form anywhere on the skin, but they tend to grow on the chest, back, and face. These melanomas can also grow on areas of skin that usually aren’t exposed to the sun. Males commonly develop nodular melanomas on their chest or back, according to the National Cancer Institute.

3. Lentigo Maligna

Lentigo maligna — also known as melanoma in situ — is the first stage of melanoma. Also known as stage 0 melanoma, lentigo maligna is the easiest type to treat. These lesions are flat and grow horizontally on the skin for several years.

If a lentigo maligna starts to grow deeper into the skin, it can become lentigo maligna melanoma. This type of melanoma accounts for around 5 percent of all cases.

Older adults are most likely to develop lentigo maligna melanoma on the face and other sun-exposed areas. Many people mistake lentigo maligna melanoma for age spots. The lesions may be flat brown or tan patches that get darker over time.

4. Acral Lentiginous Melanoma

Around 8 percent of melanomas are acral lentiginous melanoma (ALM) — the most common type affecting people with darker skin tones. According to the National Cancer Institute, up to 70 percent of melanoma cases in Black people and up to 46 percent in Asian people are ALMs.

Unlike other types of melanoma, ALM doesn’t affect areas of skin with more sun exposure. Instead, this type mainly forms on the fingernail beds, palms of the hands, and soles of the feet.

With an ALM, you may notice:

• A new mole or spot that’s darker than the skin around it
• A new or irregularly shaped spot on your hand or foot that’s changing or growing
• A new mark or streak in your nail that wasn’t caused by a bruise or injury
• A patch of thickened skin growing on your hand or the bottom of your foot

ALMs are also considered extremely aggressive because they grow fast and spread deep within the skin quickly. There are also misconceptions that people with dark skin tones don’t develop melanoma and that melanomas only develop on skin exposed to the sun. This can contribute to delayed diagnose and treatment.

Rare Types of Melanoma

There are several other types of melanoma, each accounting for less than 5 percent of melanoma cases.

5. Mucosal Melanoma

Mucosal melanoma develops on the mucosal (moist) tissues lining the mouth, nose, throat, anus, and genitals. Because mucosal melanomas are harder to find, they tend to be diagnosed at a later stage and spread quickly. Overall, mucosal melanomas account for 1 percent of cases.

Symptoms of mucosal melanoma vary depending on where the tumors are. For example, mucosal melanoma in your mouth can cause pain, bleeding, or the formation of lumps or sores.

6. Desmoplastic Melanoma

Desmoplastic melanomas account for 4 percent of all cutaneous melanomas. These melanomas develop in the dermis (deeper layer of skin). They tend to look like scars or lumps that are the same color as your skin. This is why desmoplastic melanoma can be harder to diagnose.

Adults over the age of 60 are more likely to develop desmoplastic melanoma. You may notice lesions on areas of skin that get sun exposure — like your scalp, face, neck, arms, and legs.

7. Spitzoid Melanoma

Spitzoid melanoma is a type of melanoma that looks similar to a Spitz nevus. A Spitz nevus is a harmless mole that usually develops during childhood. Because these two lesions look so similar, it can be hard to tell them apart. If you notice a growing or changing mole or bump that’s red, brown, or black, you may have Spitzoid melanoma.

8. Ocular Melanoma

Ocular melanoma affects the pigment-producing cells found in the eyes. It usually begins in the uvea — the middle layer of your eye. In rare cases, ocular melanoma can also develop in the conjunctiva or the clear layer covering your eye. Symptoms of ocular melanoma include dark spots in your eyes and blurry vision.

9. Amelanotic Melanoma

Amelanotic melanoma refers to melanomas that are pink, red, or flesh-colored. They’re usually harder to tell apart from other skin conditions. As a result, amelanotic melanoma is usually diagnosed later compared to other types. Around 5 percent of melanomas are amelanotic.

Understanding the range of melanoma types is key to catching it early, which is when treatment tends to work best. Melanoma comes in different forms, each with its own set of warning signs. By being proactive and knowledgeable about these signs, you can quickly notice any unusual changes to your skin.

If you see anything new or odd, getting a professional opinion from your doctor is crucial. Keeping an eye on your skin health is a smart step toward staying healthy.

Talk With Others Who Understand

MyMelanomaTeam is the social network for people with melanoma and their loved ones. On MyMelanomaTeam, members come together to ask questions, give advice, and share their stories with others who understand life with melanoma.

Have you or a loved one been diagnosed with melanoma? What type? Share your experience in the comments below, or start a conversation by posting on your Activities page.