Nodular melanoma may not show the same warning signs as other types of skin cancer, making early detection challenging. Nodular melanoma is a fast-growing type of melanoma, typically developing over several weeks or months. Unlike other melanomas that spread horizontally, nodular melanoma grows vertically into the skin and can also protrude above the surface, forming a noticeable nodule (lump). These nodules are often wider and taller than typical moles. Nodular melanoma can appear anywhere on the skin but is more commonly found on sun-exposed areas.

Nodular melanoma is categorized into four stages, often written with Roman numerals, such as “stage IV” for stage 4. Unfortunately, nodular melanomas are frequently diagnosed at later stages when the tumor is thicker. However, early diagnosis is key to a better prognosis (outcome), which is why it’s so important to be able to recognize symptoms.

In this article, we describe seven nodular melanoma symptoms to watch for and when it’s time to talk to your dermatologist.

Nodular Melanomas Don’t Always Follow Melanoma Skin Cancer Warning Signs

If you have a history of skin cancer or are at risk of skin cancer, you may be familiar with the “ABCDE” rule for recognizing signs of melanoma:

• Asymmetry
• Irregular border
• Uneven color
• Diameter greater than 6 millimeters
• Evolution of the mole

However, signs and symptoms of nodular melanomas don’t always follow these rules and can be missed during self-evaluations.

Therefore, it’s important to know which symptoms might signify nodular melanomas, even if they don’t match the “ABCDE” guide. Below are seven examples of what nodular melanomas can look and feel like to help you know when it’s time to see your dermatologist, potentially improving your chances for early detection.

1. Discoloration or Lack of Color

Nodular melanomas often appear as a discolored lump on your skin. They are usually brown, pink, red, black, or blue-black. Sometimes they can look like other skin lesions, such as moles, pimples, insect bites, or blood blisters. Some nodular melanomas are the same as your skin color — or they may be colorless (lack pigment). According to DermNet, 33 percent of nodular melanomas are colorless.

Although the color of a nodular melanoma can make it hard to tell it apart from normal skin blemishes, knowing more characteristic signs can help you tell the difference.

2. Smooth or Rough Texture

Nodular melanomas can range in texture, from smooth to rough or crusty, with some resembling the texture of cauliflower. The surface may also resemble a wart.

3. Rapid Growth

Nodular melanomas are characterized by rapid growth, a key symptom that often draws attention. The lump can enlarge significantly over weeks to months.

Some signs of skin cancer, like multiple colors in a mole or irregular borders, don’t always apply to nodular melanomas. Therefore, it can be hard to tell if a growth warrants concern. However, a rapidly developing growth is a telltale sign for diagnosing nodular melanoma in the early stages.

4. Dome-Shaped and Symmetrical

Nodular melanomas are often dome-shaped and symmetrical. They are usually bigger than moles, measuring more than 1 centimeter across and 6 millimeters high. This makes them stand higher than the surrounding skin.

Sometimes nodular melanomas appear as balls of skin on a stalk, or like mushrooms on a stem, but that is less common.

Another reported symptom of nodular melanomas, specifically thin nodular melanomas (2 millimeters or greater), is a growth that quickly changes shape — such as a round mole becoming oblong — or develops irregular borders.

Because nodular melanomas are generally symmetrical, they don’t always look like other forms of skin cancer for which asymmetry is a key warning sign. Although nodular melanomas can have an asymmetrical structure, this may only be visible with a dermoscope, a magnifying tool dermatologists use to examine the skin.

5. Firm to the Touch

Nodular melanomas often feel firm or hard. One study found that people with thick nodular melanomas (greater than 2 millimeters) described them as hardened, like a “hard pimple,” and that squeezing one “felt like cracking open a peanut.”

6. Bleeding or Oozing

Nodular melanomas can bleed and ooze, often triggered by irritation such as scratching, squeezing, or poking it — though sometimes, they may bleed on their own. Oozing can also occur with slight irritation. One study indicated that individuals with thick nodular melanomas found them sensitive and prone to easily breaking open and oozing after activities drying off with a towel.

7. Itchiness and Pain

Nodular melanomas may itch, sting, or be otherwise painful. A growth becoming itchy over time may be an early sign of nodular melanoma. Some people have also reported nodular melanomas becoming itchy, erupting, or being itchy, sore, and sensitive.

When To See Your Dermatologist

If you notice an unusual growth on your skin, it’s time to see a dermatologist. Consult your dermatologist if you see any of the following symptoms of a skin growth:

• Changes in shape or color
• Bleeding or itchiness
• Firmness to the touch
• Rapid growth

Nodular melanoma is aggressive, making it all the more important to catch it early when treatment is easiest.

In addition, it’s important to tell your dermatologist or health care provider if you have certain skin cancer risk factors, such as a family history of skin cancer, having had skin cancer yourself, or lots of sun exposure in your life.

Tumor Thickness and Prognosis

Detecting nodular melanomas in their early stages can be challenging because symptoms often don’t appear until the tumor has grown. For instance, a study found that individuals with thick nodular melanomas reported more symptoms, such as bleeding and itching, in the year before diagnosis compared to those with thinner nodular melanomas.

Nodular melanomas tend to be thicker than other types of melanomas, though most of the growth is under the skin’s surface. Thick nodular melanomas indicate later stages of the cancer. For example, a nodular melanoma greater than 2 millimeters but that hasn’t spread is categorized as stage 2.

The thicker the tumor, the higher the risk to nearby lymph nodes or internal organs. Experts estimate a 5 percent risk of spread for nodular melanomas 0.75 to 1 millimeter thick, compared to 40 percent for those over 4 millimeters thick.

Nodular melanomas often grow beneath the skin's surface, making their thickness difficult to assess just by looking. Because of this, it’s crucial to inform your dermatologist about any signs or symptoms of nodular melanoma that you can see or feel.

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 been diagnosed with nodular melanoma? What symptoms did you have? Share your experience in the comments below, or start a conversation by posting on your Activities page.