Nodular Melanoma

Nodular melanoma is an aggressive type of skin cancer that grows quickly and deeply into the skin. Though it represents only 15% to 20% of all melanoma cases, it causes about half of all melanoma-related deaths, making early detection and treatment critical.

Table of contents

• What is nodular melanoma?
• How nodular melanoma looks
• Stages of nodular melanoma
• Causes and risk factors
• Who is affected
• Diagnosis
• Treatment options
• Outlook and survival
• Prevention

What is nodular melanoma?

Nodular melanoma is a type of skin cancer that develops from cells called melanocytes, which are the cells that give your skin its color^[1]. It is the second most common type of melanoma, accounting for approximately 10% to 15% of all melanoma diagnoses^[4]. However, it is responsible for over 40% of all melanoma-related deaths^[4].

What makes nodular melanoma particularly dangerous is the way it grows. Unlike other types of melanoma that first spread outward across the skin’s surface, nodular melanoma grows downward into the deeper layers of skin from the very beginning. This pattern is called vertical growth^[1]. The cancer develops very quickly, usually growing rapidly over several weeks to months^[1].

Think of nodular melanoma like an iceberg: it grows above and below your skin, but most of the cancer is below the surface where you cannot see it^[1]. This deep growth means it can penetrate into tissues, bones, and lymph nodes (small organs that are part of your body’s defense system) within weeks or months, which is when the cancer becomes harder to treat^[5].

How nodular melanoma looks

Nodular melanoma typically appears as a firm, raised bump or lump on the skin^[1]. The growth is usually dome-shaped and can look like a blood blister^[1]. Most commonly, it appears as a round black bump, but it can also be blue, gray, red, white, pink, tan, or even the same color as your surrounding skin^[5]. About 5% of nodular melanomas do not have an unusual color and appear flesh-toned, which makes them harder to recognize^[5].

The texture may be smooth, crusty, or rough, somewhat like cauliflower^[1]. Nodular melanomas are usually larger than typical moles on your skin, generally greater than 1 centimeter in diameter (about the length of a staple) and higher than 6 millimeters (about the height of 60 sheets of paper)^[1].

Common symptoms include bleeding, itching, or stinging^[1]. The melanoma may bleed if you poke, scratch, or squeeze it, but it may also bleed on its own without any disturbance^[1]. The growth feels hard or firm to the touch^[1].

Nodular melanoma can be difficult to recognize because it does not follow the usual warning signs for melanoma. You may have heard about checking for moles that are asymmetrical, have uneven borders, different colors, or are spreading. However, nodular melanomas are different—they usually appear as round bumps with even borders and solid colors^[5]. Because of this, nodular melanoma can sometimes look like other benign (non-cancerous) skin conditions such as moles, bug bites, pimples, or even harmless growths^[4].

Stages of nodular melanoma

Healthcare providers classify nodular melanoma into different stages based on how much the cancer has spread^[1]:

Stage 0 (melanoma in situ): The nodular melanoma is only in the top layer of your skin, called the epidermis. It has not spread from its original position^[1].

Stage I: The nodular melanoma is low-risk, and there is no evidence that it has spread. It is small—less than 2 millimeters thick^[1].

Stage II: The nodular melanoma is thicker than 2 millimeters. It has features that indicate a higher risk of coming back after treatment. However, there is no evidence that it has spread^[1].

Stage III: The nodular melanoma has spread to nearby lymph nodes or nearby skin^[1].

Stage IV: The nodular melanoma has spread to more distant lymph nodes or skin, or it has spread to your internal organs^[1].

The thickness of the tumor is an important factor in determining the stage. Thicker tumors have a higher risk of spreading to other parts of the body and coming back after treatment^[4].

Causes and risk factors

The biggest risk factor for developing nodular melanoma is overexposure to ultraviolet (UV) light, especially from sunburns^[1]. UV light comes from the sun or from artificial sources like tanning beds. These rays can harm your skin’s DNA over many years or even decades^[5].

Your skin contains melanocytes, which produce melanin—the substance that gives your skin its color. UV exposure from the sun or tanning beds can cause the DNA in your melanocytes to change. When this happens, the melanocytes can grow and divide uncontrollably and invade nearby tissues, leading to cancer^[1].

Not all nodular melanomas are directly caused by UV rays. Although less common, they can also develop on parts of your body that are not exposed to the sun^[5]. Experts believe the development of melanoma is probably due to a combination of your genes, lifestyle habits, and UV exposure^[5].

Other factors that increase your risk of developing nodular melanoma include^[1]:

• Having had skin cancer before
• Having a family history of skin cancer
• Having fair skin that burns easily
• Spending a lot of time in the sun
• Having multiple unusual-looking moles or many moles
• Having a weakened immune system or taking immunosuppressant drugs

Nodular melanoma is not contagious. You cannot catch it from or give it to another person^[1].

Who is affected

Anyone can develop nodular melanoma, but certain groups of people are at higher risk. It is more common in men than in women^[5]. The disease is most often found in men ages 50 and older^[5]. Most cases are diagnosed in people who are in their 40s and 50s^[7].

Nodular melanoma is more likely to occur in people with very fair skin (those who burn easily and do not tan), although it may also occur in those who tan quite easily, and occasionally in people with brown or black skin^[8].

Diagnosis

If you notice a new growth or spot on your skin that does not go away within 5 days, or if you see any changes in an existing mole, you should see your doctor^[5]. Do not try to pop or squeeze the growth, as this will just cause a wound^[5].

A skin specialist called a dermatologist will examine your skin. If a spot or bump looks suspicious, the doctor may use a tool called a dermatoscope to get a better look at the growth^[8]. The most frequently observed features of nodular melanoma under a dermatoscope include a disorganized asymmetrical structure, unusual blood vessel patterns, blue-grey structures, and multiple colors^[8].

If the doctor suspects nodular melanoma, you will need a biopsy. This is when the doctor removes some or all of the growth and sends the tissue to a laboratory for testing^[5]. A doctor called a pathologist will look at the tissue and cells under a microscope to check if it is nodular melanoma^[5].

The pathologist can also measure the melanoma’s thickness, which helps determine the cancer’s stage. The thicker the melanoma, the more it has grown into the skin^[5].

If the melanoma is more than 1 millimeter thick, you will probably need a biopsy of your lymph nodes. This may help doctors find out if the cancer has spread to other parts of your body^[5]. Those with melanoma that is more than 1 millimeter thick may also be advised to have imaging studies and blood tests^[8].

Treatment options

Your treatment will depend on how much the cancer has spread and what stage it is in^[5].

Surgery

Surgery is the main treatment for nodular melanoma, especially if it is found early^[1]. Surgical removal with wide margins is considered the gold standard of nodular melanoma treatment^[4].

The surgeon will remove the melanoma, plus some of the normal skin surrounding it and a layer of tissue beneath it^[5]. Removing an area of healthy skin around the cancer helps lower the chances of it coming back^[1].

If a large area of skin needs to be removed, skin may need to be taken from another part of your body and used to cover the area where the melanoma was. This is called a skin graft^[1].

You may also need surgery if the melanoma has spread to other areas of your body, such as to remove swollen lymph nodes or melanoma that has spread to other organs^[1].

Immunotherapy

Immunotherapy medicines help your immune system find and kill cancer cells^[1]. These treatments are sometimes used for melanomas that cannot be treated with surgery, have spread to nearby lymph nodes, or have spread to other areas of the body^[1].

Targeted medicines

Targeted medicines aim to stop the cancer from growing^[1]. Before having targeted medicines, a sample of the melanoma is usually tested to check for changes in certain genes. This helps doctors decide if this type of treatment is likely to work for you^[1].

Targeted medicines and immunotherapy are sometimes used to treat melanomas that cannot be treated with surgery, have spread to nearby lymph nodes, or have spread to other areas of the body^[1].

Radiotherapy

Radiotherapy (radiation treatment) is sometimes used to reduce the size of large melanomas and help control and relieve symptoms^[1]. You may have one or several sessions of radiotherapy, depending on the area of your body being treated and whether you are also having other types of treatment^[1].

Chemotherapy

Chemotherapy uses medicines to kill cancer cells. It is sometimes used to treat advanced melanoma where the cancer has spread to another part of the body^[1]. Chemotherapy does not work as well for melanoma as other treatments like targeted medicines and immunotherapy, but it might be used if you are unable to have other treatments^[1].

Outlook and survival

Survival rates vary depending on when the melanoma is detected and how far it has spread. If melanoma is detected and treated before it spreads to lymph nodes, the 5-year survival rate is approximately 99%^[4]. However, if it spreads to nearby lymph nodes, this rate declines to 66%, and if it spreads to distant lymph nodes or organs, the rate drops to 27%^[4].

Nodular melanoma has a poorer outlook compared to other types of melanoma because it grows down into the layers of the skin rather than spreading outward first^[4]. The thickness of the tumor, whether it has ulceration (an open wound on the surface), and whether cancer has spread to lymph nodes are all important factors that affect the prognosis^[4].

You will have regular check-ups during and after any treatments. Depending on the stage of your melanoma, you may have tests and scans. If you have any symptoms or side effects you are worried about, talk to your specialists—you do not need to wait for your next check-up^[1].

Prevention

If you have had one melanoma, it means you are at risk for more. However, you can protect your skin with some basic sun-safety measures^[1]:

• Avoid spending much time outside between 10 a.m. and 4 p.m., when the sun and its UV rays are strongest. An easy way to tell when the sun is too strong: when your shadow is shorter than you are.
• Every time you go outside, wear a broad-spectrum sunscreen that protects against both UVA and UVB rays. It should have an SPF of at least 30. Reapply at least every 2 hours, and more often if you are swimming, sweating, or spending time near water or snow.
• Cover your skin with pants, long sleeves, and a wide-brimmed hat.
• Wear UV-protective sunglasses outside to protect your eyes.
• Avoid tanning beds.

Check every part of your skin at least once a month, looking for any new or changing marks. Also make sure you have regular check-ups with your doctor^[1]. If you notice a new growth or spot on your skin that does not go away, see your doctor right away.