Can You Get Skin Cancer in Places the Sun Doesn't Reach?

Most of us grew up with the same mental picture of skin cancer: a suspicious mole on a sunburned shoulder, a rough patch on the back of the neck, something on the face that wasn't there before. Sun exposure, sun damage, skin cancer. The connection feels almost automatic.

And for the most part, it's accurate. The sun is behind the vast majority of skin cancers in this country. According to Cancer Council Australia, at least two in three Australians will be diagnosed with skin cancer in their lifetime, a rate that reflects decades of high UV exposure and, for many, not nearly enough protection.

But here's what that statistic doesn't tell you: skin cancer doesn't always follow the rules. It can appear in places that rarely, or never, see the sun. And because most people don't think to look there, those cancers are often found later, when they're harder to treat.

The Parts of Your Body You Probably Aren't Checking

Think about the last time you looked carefully at the soles of your feet. Or the skin between your toes. Or the nail beds on your hands and feet. Or your scalp, particularly if you have thinning hair or a parting that exposes skin to the elements.

These aren't areas most people associate with skin cancer. They're tucked away, covered, easy to overlook. Which is exactly what makes them worth paying attention to.

The soles of your feet and palms of your hands

There is a specific type of melanoma, the most serious form of skin cancer, that develops on the palms of the hands and the soles of the feet. It's called acral lentiginous melanoma, and unlike most melanomas, it's not believed to be caused by sun exposure at all. Researchers are still working to understand exactly why it develops, but what's clear is that UV radiation isn't the driver.

It typically begins as a flat, dark patch, sometimes resembling a bruise, a stain, or even a plantar wart, and slowly grows and darkens over time. Because it looks so much like something ordinary, and because it sits somewhere people rarely examine carefully, it tends to be diagnosed late.

This type of melanoma is the most common form found in people with darker skin tones, which adds another layer of complexity: skin cancer on darker skin is already less likely to be picked up early, partly because the contrast between a lesion and surrounding skin can be subtle, and partly because there's a widespread, and dangerous, misconception that people with darker skin aren't at significant risk.

Under and around the nails

Melanoma can develop under a fingernail or toenail, a subtype called subungual melanoma. It most commonly appears as a dark vertical streak running the length of the nail, often brownish or black in colour. The thumb and big toe are the most frequent sites.

It can be mistaken for a bruise, a fungal infection, or general nail discolouration, which is why it so often goes unaddressed for months or years. If a dark streak under your nail hasn't been caused by a clear injury, and it isn't growing out as the nail grows, it deserves a professional opinion. If you have a sore that refuses to heal or a mole that has changed in appearance recently, get in touch with a respected skin clinic.

The scalp

The scalp is sun-exposed in people with thinning hair or those who regularly part their hair, and it's also a site where melanomas can develop regardless of UV exposure history. Scalp melanoma represents around 2–5% of all skin melanomas, and it carries a poor prognosis largely because it's diagnosed late. Hair provides a natural concealment, and most people don't think to check their scalp, or have someone else check it for them.

If you've ever noticed an unusual spot, rough patch, or change in the skin on your scalp, it's worth having it looked at. A thorough skin check at a clinic will include the scalp.

Between the toes and around the feet

Melanoma on the foot isn't limited to the sole. It can appear between the toes, on the heel, and in other areas that are almost never exposed to the sun. In some cases it presents as a sore that doesn't heal, or one that seems to heal and then returns. Given that foot skin tends to be thicker and the area harder to self-examine, these cancers are another category that often go unnoticed until they've progressed.

The eyes and eyelids

Skin cancer, particularly basal cell carcinoma and squamous cell carcinoma, can develop on and around the eyelids. The eyelid skin is extremely thin and delicate, and it's an area people rarely think to examine closely. Any persistent lesion, thickening, or change around the eye area warrants attention.

Melanoma can also develop inside the eye itself, in the layer of cells that give the eye its colour. This is called ocular melanoma, and it has no connection to sun exposure on the skin at all, it arises from the same type of pigment-producing cells found in skin, but located within the eye.

Why These Cancers Get Found Late

There's a consistent thread running through all of these: they tend to be diagnosed later than skin cancers in more obvious locations. That's not a coincidence.

When a spot appears on your face or forearm, you're likely to notice it relatively quickly. When something unusual develops under a toenail or on the sole of your foot, weeks and months can pass before you even look there, let alone seek an opinion.

Later diagnosis means more advanced disease at the time of treatment. And more advanced disease means treatment is more complex, outcomes are less certain, and the road back is longer.

This is the core argument for a proper, head-to-toe skin check rather than a casual self-examination of the visible bits. A trained clinician won't just look at your face and arms, they'll check your scalp, between your toes, under your nails, and every other area where something could be quietly developing out of sight.

What a Full Skin Check Actually Involves

A skin check at a specialist clinic isn't the same as a quick look in a GP's office. It's a methodical, full-body examination, including the areas most people never think to include in their own self-checks.

At a skin cancer clinic, clinicians use dermoscopy (a magnifying tool that allows detailed examination of pigmented lesions beneath the skin surface) to assess spots that might look unremarkable to the naked eye. They're trained to recognise the early signs of melanoma in unusual locations, and they know what questions to ask about changes you might have noticed but not connected to skin cancer.

If you've never had a full skin check, or if it's been more than a year since your last one, that's worth acting on, particularly if you've spent significant time in the Australian sun over your lifetime. Sun exposure is estimated to cause around 95% of melanoma cases and 99% of non-melanoma skin cancers in Australia, but even the minority of cases that aren't UV-driven still need to be found early to be treated effectively.

The Takeaway

Skin cancer is not exclusively a sun-exposure story. It can develop anywhere on the body, including places you've never had a sunburn, places you can barely see, and places you've probably never thought to check.

The good news is that early detection changes outcomes dramatically. A skin cancer found early is almost always treatable. One that's been quietly growing in a hard-to-see location for two or three years before it's noticed is a different situation entirely.

Don't limit your awareness, or your skin cancer checks to the parts of you that face the sun.