A faint brown line under a fingernail might not seem like a cause for concern. But for one woman, it turned out to be the only signs of a rare, deadly kind of cancer that ultimately cost her part of her finger.
When Elizabeth Misselbrook first noticed a mysterious streak under the nail of the middle finger of her left hand in September 2019, her doctor told her not to worry.
It was, most likely, a bruise.
But within two years, the keen flute player from Bracknell, Berkshire, was forced to have part of her middle finger amputated due to the discovery of a life-threatening cancer.
Experts are now warning patients to look out for similar nail changes that could be a sign of the disease. They also warn that there are other serious medical conditions that can affect the nails too.
Elizabeth, who is now in her 40s, initially contacted her GP after remembering that she had seen a social media post outlining the dangers of mysterious lines appearing on the nail.
‘I was worried because I have a doctor friend and she put something on Facebook about a line on your nail being a sign of something,’ the marketing manager said.
Elizabeth Misselbrook first noticed a brown streak under her finger nail in September 2019
She was initially told to keep an eye on it for three months and said she wasn’t ‘overly worried’
‘I wasn’t overly concerned – but enough to make a GP appointment. I didn’t wait. It didn’t itch, it was just a faint, light brown line.’
After being reassured by the doctor, she was told to return in a few months if it hadn’t resolved.
Elizabeth noticed that, far from fade away, it began to grow and darken – and when she returned to the GP, he referred her to a dermatologist.
Elizabeth said: ‘It takes time because it’s not a quick ‘whip that off and have a look’ and nails do get funny marks. But it was changing and I did have a bad feeling.’
Doctors decided the safest way to investigate was to remove the nail so they could examine the tissue underneath.
This is standard practice when melanoma is suspected, as the cancer develops in the nail bed – the skin beneath the nail – rather than the nail itself.
The procedure involves taking off the nail plate under local anaesthetic and removing a sample – or sometimes all – of the underlying tissue for biopsy.
In Elizabeth’s case, surgeons went further and removed the entire nail bed down to the bone, before covering the area with a skin graft to help it heal.
Because the nail-producing cells sit in the nail bed, removing this tissue usually means the nail will not grow back normally. However, depending on how much of the structure remains, some regrowth or a nail-like covering can occur.
When the area healed, her nail returned with a more sinister appearance, defined by a ‘much darker and wider’ line in December that year – a sign the abnormal pigment cells were still present and progressing.
‘It was changing a lot,’ Elizabeth recalled. ‘The dermatologist said it was suspicious and it’d need to be biopsied again. It was much wider and darker and I was getting worried.
‘It had pigment that had gone onto skin at base of nail so I was a lot more concerned because it had more sinister features.’
Elizabeth was diagnosed with acral lentiginous subungual melanoma in May 2021.
‘They said it’s melanoma, stage 1A meaning it’s invasive but not hugely,’ she said.
The disease, which manifests itself under the nail in dark lines, is often ignored – or even missed – because it often looks like a simple bruise. Though if it is not caught quickly it can be aggressive and highly dangerous.
Elizabeth was aware of the dangers and even spotted a third lesion on her nail.
Within two years Elizabeth was forced to have part of her middle finger amputated
Elizabeth was a keen flute player before having her finger amputated
That led doctors to give Elizabeth the devastating news that she should have part of her finger removed in July 2022 because the cancer had already occurred twice.
She reluctantly agreed out of desperation to live.
Elizabeth said: ‘I was upset when they said they had to amputate, but I was really worried so I kind of wanted them to make sure it didn’t come back. I was resigned to it.
‘I hadn’t felt unwell at any point and I hadn’t had drug treatment so I felt grateful. I didn’t want to get ill.
‘I was worried about the long-term consequences like handwriting and playing the flute. I wanted to play the flute but I want to live more.’
Elizabeth said she would not have been aware of the dangers of having a line under the nail if it was not for the post she had seen on social media.
Speaking after her second melanoma was removed – leaving her cancer free – she added: ‘The whole way along I never felt I was going to die because the surgeon was very reassuring that it was cancer but it was very treatable as it was diagnosed early.
‘I was trying to stay calm and thinking ‘it is what it is, I’ve got to deal with it and it’s not nice’. A lot of people struggle a lot more than I have and they find it really hard.’
With around 17,600 new cases of melanoma in Britain every year, and between one and three per cent are subungual melanoma.
Plastic surgeon Richard Wain, an expert in skin cancer, said: ‘It can happen in any nail – on your hands or feet – and unlike other forms of melanoma, it’s not related to UV exposure.
‘We don’t really know what the cause is.’
Typically, subungual melanoma is first detected when someone visits their doctor after noticing what they believe is a bruise under the nail that isn’t going away.
But in rare instances, cancer is discovered.
‘For this reason, it’s sometimes associated with trauma in people’s minds – but we don’t know whether trauma actually causes it.’
In addition, people with darker skin tones, including those from Asian backgrounds, may develop a benign change to the nail known as melanonychia – black or brown streaks down the nail.
‘This is usually seen in multiple fingers or toes and is harmless,’ said Mr Wain. ‘The thing to look out for is a line or mark in a single digit that changes.
‘One of the big problems, from my perspective, is that a lot of patients present quite late – they watch it and think it’s fine, then eventually go to the doctor.
‘My feeling with this kind of thing is: if you notice a dark patch that wasn’t there before and don’t remember injuring it, go and see your GP – and take a picture.
‘The worst thing is to wait months and months for it to grow, and only come to clinic when it could have been treated earlier.
‘When it’s treated later, you may have to remove the finger – and it can kill, absolutely it can.
‘We can often treat it locally, but if it’s very thick, we have to amputate the whole finger.’
Elizabeth, who is mystified about what could have caused her condition, wants to raise awareness over the rare disease.
‘Check your nails for anything suspicious that doesn’t grow out, a bruise will grow out,’ she said.
Experts have echoed her calls, and have urged people to be more aware of the subtle warning signs.
Unlike many forms of skin cancer, subungual melanoma is not linked to sun exposure. Instead, its causes are still not fully understood, though trauma to the nail, genetic factors and existing pigmentation may play a role.
The condition can also affect toenails, where it is even more likely to go unnoticed.
Specialists say the key warning sign is a single dark line running from the base of the nail to the tip that does not fade or grow out. Changes in colour, width, or pigment spreading onto the surrounding skin should also raise concern.
