Melanoma can look like a dark, irregularly shaped mole, a pink bump, a bruise under a fingernail, or even a spot that resembles a scar. It varies more in appearance than most people expect, which is exactly why knowing the specific visual patterns matters. While photos from a dermatologist or cancer center can help you compare (the National Cancer Institute and Memorial Sloan Kettering both maintain image galleries), understanding the features to look for is just as important as matching a picture.
The ABCDE Features of Early Melanoma
Most melanomas that develop from existing or new moles share five visual warning signs, commonly called the ABCDE rule. These features apply to the most common type, superficial spreading melanoma, which accounts for roughly 70% of cases.
- Asymmetry. If you drew a line through the middle of the spot, the two halves wouldn’t match in shape or color.
- Border irregularity. The edges are ragged, notched, or blurred rather than smooth and round. Pigment may appear to bleed or spread into the surrounding skin.
- Color variation. Instead of one uniform shade of brown, you see a mix: tan, brown, black, and sometimes patches of white, gray, red, pink, or blue within the same spot.
- Diameter. Most melanomas are larger than 6 millimeters (about the width of a pencil eraser) by the time they’re noticed, though they can be smaller when first developing.
- Evolving. The spot has changed in size, shape, color, or texture over weeks or months. Any mole that looks different from how it looked before deserves attention.
Of these five features, “evolving” is often the most reliable for catching melanoma early. A mole that has looked the same for years is far less concerning than one that started changing recently, even if it doesn’t check every other box.
What Nodular Melanoma Looks Like
Nodular melanoma doesn’t always follow the ABCDE pattern. Instead of spreading outward as a flat spot, it grows vertically into the skin from the start, forming a firm, dome-shaped bump. It can be dark brown or black, but it sometimes looks like a blood blister or a shiny, dark-colored nodule. It develops fast, often growing noticeably over just weeks to months.
Because nodular melanoma tends to be round and symmetrical, people sometimes dismiss it as a pimple or insect bite that won’t heal. The key giveaways are that it’s firm to the touch, elevated above the skin surface, and continues growing rather than resolving. A bump that persists for more than three to four weeks and keeps getting bigger is worth having checked.
Pink and Red Melanomas Without Dark Color
Not all melanomas are dark. Amelanotic melanoma appears as a pink, red, or skin-colored spot because the cancer cells produce little to no pigment. It can look like a small sore, a pimple that doesn’t heal, or a patch of irritated skin. Because it lacks the brown and black coloring people associate with melanoma, it’s frequently overlooked or mistaken for something harmless. Memorial Sloan Kettering notes that amelanotic melanoma is often diagnosed at a later stage for exactly this reason.
If you have a pink or reddish bump or patch that persists, doesn’t respond to typical skin treatments, and slowly changes in size or shape, it’s worth a closer look, especially if it bleeds easily or has an uneven surface.
Melanoma on Palms, Soles, and Dark Skin
Acral lentiginous melanoma develops on the palms of the hands, soles of the feet, or under nails. It’s the most common type of melanoma in people with darker skin tones, though it can affect anyone. In its early stages, it appears as a light-to-dark brown or black flat patch that follows the natural skin ridges on the palm or sole. The color is often uneven, with darker areas mixed with lighter ones, and the edges are irregular.
As it progresses, it can become raised, develop a nodular bump, or ulcerate. An increasing number of colors within the spot, particularly blue and black tones, suggests the melanoma is becoming more invasive. Because these areas of the body aren’t typically checked during casual self-exams, acral melanoma often goes unnoticed longer than melanomas on more visible skin.
Dark Streaks Under a Nail
Subungual melanoma, which develops under a fingernail or toenail, looks like a dark vertical streak running the length of the nail. The streak is typically blackish-brown and irregular in color, often darker in some areas than others. Early on, the line may be narrow (under 3 millimeters wide), but it tends to widen over time, usually starting at the base of the nail.
One important sign is called Hutchinson’s sign: the dark pigment spreads beyond the nail itself and discolors the surrounding skin at the nail fold. This pigment bleed is a strong indicator of melanoma rather than a benign nail streak. Not every dark line under a nail is melanoma (minor trauma and normal pigmentation can cause them too), but a streak that’s new, widening, or accompanied by nail distortion or pigment spreading onto the skin should be evaluated.
Spots That Look Like They’re Fading
Some melanomas undergo partial or complete regression, where the immune system attacks part of the tumor. Visually, this creates an unusual patchwork: areas of the lesion lose their color and turn white, gray, or blue-gray, while other areas remain pigmented. The spot can range from about 4 millimeters to 3 centimeters across and may shift between lighter and darker over time.
A mole that seems to be “disappearing” on its own isn’t necessarily a good sign. Regression can mean the body is fighting the melanoma, but the cancer may still be present deeper in the skin or may have already spread. A spot with an odd mix of pigmented and depigmented zones, especially if it previously looked different, still warrants evaluation.
How to Tell Melanoma From Harmless Spots
Several common skin growths can mimic melanoma’s appearance. Seborrheic keratoses, the waxy, “stuck-on” looking brown growths common in middle-aged and older adults, are one of the most frequent look-alikes. The key visual difference: seborrheic keratoses have sharply defined borders and an undulating, waxy surface texture, often with tiny pitted openings visible on close inspection. Melanomas tend to have a smoother, sometimes glistening surface and borders that fade into the surrounding skin rather than sitting on top of it like a sticker.
Ordinary moles are typically uniform in color (one shade of brown), symmetrical, and smaller than 6 millimeters. They may be flat or raised, but they look the same month after month. The simplest screening approach is the “ugly duckling” method: if one mole looks noticeably different from all the others on your body, it deserves a closer look, even if it doesn’t perfectly match any melanoma description.
What Dermatologists See That You Can’t
During a skin check, dermatologists use a handheld magnifying tool called a dermatoscope that reveals structures invisible to the naked eye. Under magnification, melanomas show patterns like irregular pigment networks (a mesh-like pattern with uneven lines and spacing), streaks or irregular dots and globules of pigment, and a blue-white veil, which is a hazy blue-gray film over part of the lesion. These microscopic features help distinguish melanoma from benign growths that can look similar on the surface.
This is why a photo comparison at home, while useful for deciding whether to make an appointment, can’t replace a professional evaluation. Many melanomas look ambiguous to the naked eye, and some truly suspicious-looking spots turn out to be harmless. The visual features described above are your best screening tool, but the final answer always comes from a biopsy, where a small sample of the spot is examined under a microscope.