You’ve probably looked at your hands a thousand times today. Maybe you noticed a chipped polish or a hangnail, but most of us ignore the actual anatomy of the nail until something looks weird. When people start searching for photos of nail melanoma, it’s usually because they’ve spotted a dark line and the panic is starting to set in. Is it just a bruise? Or is it something that requires a surgeon? Honestly, subungual melanoma—the medical term for skin cancer under the nail—is pretty rare, accounting for only about 0.07% to 3.5% of all melanomas worldwide. But because it’s often mistaken for a simple fungus or a "door-slam" injury, it gets diagnosed late. That delay is the real killer.
Subungual melanoma doesn't look like the typical mole on your back. You aren't looking for a crusty brown circle. Instead, you're looking for pigment that starts at the cuticle and creeps up the nail plate like a slow-moving ink stain.
Why Photos of Nail Melanoma Can Be So Confusing
If you scroll through medical databases like VisualDx or the American Academy of Dermatology archives, you’ll see that photos of nail melanoma vary wildly. One person might have a crisp, dark brown line that looks like it was drawn with a fine-liner pen. Another might have a blurred, purple-grey smudge that looks exactly like they hit their thumb with a hammer three weeks ago. This is where the danger lies. A subungual hematoma (a bruise) will eventually grow out with the nail. Melanoma won't. If that line stays in the exact same spot relative to your cuticle for a month, you aren't looking at a bruise.
Medical experts like Dr. Shari Lipner, a leading dermatologist at Weill Cornell Medicine, often point out that subungual melanoma most frequently hits the "power digits." We're talking about the thumb, the big toe, and occasionally the index finger. Why? Nobody is 100% sure, though some theories suggest these digits face more trauma, though it's important to clarify that unlike most skin cancers, nail melanoma isn't strictly tied to sun exposure. It's more about genetics and internal cellular glitches.
The Hutchinson Sign: A Major Red Flag
There’s one specific thing you’ll see in many photos of nail melanoma that should immediately trigger a doctor’s visit. It’s called the Hutchinson sign.
Imagine the dark pigment isn't just on the nail itself but actually spills over onto the surrounding skin—the cuticle or the nail fold. That’s bad news. In a healthy nail, the "matrix" (where the nail is born) produces the hard plate, and any staining stays on that plate. When the cancer cells start migrating into the surrounding skin, that’s a clinical sign that the lesion is likely malignant. If you see pigment on the skin around the nail, stop reading this and call a dermatologist. Seriously.
👉 See also: Why the Dead Bug Exercise Ball Routine is the Best Core Workout You Aren't Doing Right
But here’s a twist: some people have something called ethnic melanonychia. This is totally benign. It’s very common in people with darker skin tones and often shows up as multiple brown lines across several fingers. It’s symmetrical and harmless. Melanoma, on the other hand, is almost always a "loner." It usually shows up on just one finger. If you have lines on ten fingers, it's probably just your biology. If it’s just the right thumb and it’s getting wider? That’s the one to worry about.
Distinguishing Between Fungus and Malignancy
Doctors see a lot of people who think they have a stubborn fungus when they actually have a tumor. And vice versa. Onychomycosis (nail fungus) can turn the nail yellow, white, or even blackish-green. However, fungus usually makes the nail thick, brittle, and chalky. It crumbles. Melanoma usually leaves the nail surface relatively smooth at first, though as the tumor grows under the plate, it might cause the nail to split down the middle.
What the "ABCD" Rule Looks Like for Nails
You might know the ABCD rule for moles, but for nails, it’s a bit different. Experts often use the "ABCDEF" mnemonic specifically for subungual cases:
- A stands for Age. It’s most common in the 50 to 70 age range.
- B is for Band. Look for a band that is brown or black and wider than 3 millimeters.
- C is for Change. Is the band getting wider? Is the border becoming blurry?
- D is for Digit. Remember the thumb or big toe priority.
- E is for Extension. That’s the Hutchinson sign we talked about—pigment on the cuticle.
- F is for Family history. If your mom or dad had melanoma, your risk profile changes.
Looking at photos of nail melanoma, you’ll notice that the "B" (Band) is often the most striking feature. A narrow, 1mm line that stays narrow is usually a benign nail mole (a lentigo). A line that starts at 2mm and grows to 5mm over six months is a massive warning sign.
The Role of Biopsy and Diagnosis
You can't diagnose yourself with a Google Image search. You just can't. Even the best dermatologists use a tool called a dermoscope—basically a high-powered magnifying glass with polarized light—to look at the patterns of the pigment. If they see "parallel ridge patterns" or irregular "globules" of pigment, they’ll order a biopsy.
✨ Don't miss: Why Raw Milk Is Bad: What Enthusiasts Often Ignore About The Science
A nail biopsy sounds terrifying. I’m not going to sugarcoat it: they usually have to remove a small circular "punch" of the nail and the underlying tissue, or sometimes the entire nail plate, to get a clear sample. It’s done under local anesthesia. It’s uncomfortable, but it’s the only way to know for sure. If the biopsy confirms melanoma, the treatment usually involves removing the entire nail unit. In the past, doctors used to just amputate the tip of the finger. Thankfully, modern surgical techniques like Mohs surgery or wide local excision often allow patients to keep their finger, even if the nail is gone forever.
Misconceptions That Delay Treatment
One of the biggest myths is that "it doesn't hurt, so it’s fine."
Cancer is famously quiet.
Early-stage subungual melanoma is completely painless. You won't feel a throb. You won't feel pressure. By the time it hurts, the tumor has usually grown large enough to start eroding the bone underneath.
Another misconception is that nail polish protects you. Actually, polish is the enemy of early detection. Many cases are found by manicurists who notice a weird line when the polish comes off. If you wear gel or acrylics constantly, you might go a year without actually seeing your natural nail. Make it a habit to check your bare nails for at least a few hours between appointments.
Actionable Steps If You're Worried
If you’ve been staring at photos of nail melanoma and comparing them to your own hand, here is exactly what you should do next. Don't just sit in a state of "maybe."
First, do the "blanch" test. Press down on the dark spot. If it’s a bruise (blood under the nail), the color might shift slightly or the pressure might feel specific. If it's a pigment line in the nail itself, it won't move.
🔗 Read more: Why Poetry About Bipolar Disorder Hits Different
Second, take a high-quality photo today. Use a macro lens if your phone has one. Put a ruler or even a coin next to the nail for scale. Wait four weeks. Take another photo in the exact same lighting. Has the line moved toward the tip of your finger? If the "bottom" of the line (near the cuticle) has moved up, that’s great—it’s a bruise or a stain that’s growing out. If the line still starts exactly at the cuticle, it’s being produced by the nail matrix, and you need a professional opinion.
Third, book an appointment with a board-certified dermatologist, not a general practitioner. General doctors are great, but they don't see enough subungual melanoma to always catch the subtle signs. Tell the receptionist specifically, "I have a pigmented streak on my nail and I’m concerned about subungual melanoma." That usually gets you an appointment faster than "I have a skin thing."
Finally, check your toes. We ignore our feet. People go years without looking at their pinky toes. If you find a dark patch under a toenail that you thought was just "runner's toe" or a fungal infection that hasn't cleared up with over-the-counter creams, get it checked. Most "stubborn fungus" that doesn't respond to treatment is actually something else entirely.
Early detection changes everything. When caught in "Stage 0" (melanoma in situ), the survival rate is nearly 100%. When caught late, after it has spread to the lymph nodes, that number drops significantly. Your life is worth more than the temporary discomfort of a nail biopsy. Take the photo, watch for growth, and get a professional eyes-on look.