5 symptoms of Nail Cancer that can go unnoticed

When we talk about Cancer, Nail Cancer is a condition that does not come up often. However, Nail Cancer, also known as subungual melanoma, is a rare but serious form of skin cancer that develops under the nail, typically as a dark streak running vertically down the nail. Initially, the cancer can be brushed apart as regular (and harmless) nail issues, but over time, it can turn aggressive and terminal. Like all Cancers, early detection is extremely important, and here are 5 signs you should look out for that might otherwise go unnoticed.

One of the most common early signs of nail cancer is a brown or black streak running vertically under the nail. This streak is usually about 3 millimeters wide but can grow wider over time. It may look like a bruise (that occurs due to injury), but unlike a bruise, it does not heal or move as the nail grows. This dark line is often found on the thumb or big toe but can appear on any nail.
Because it resembles a regular bruise, many people ignore it or assume it’s caused by injury. However, if you notice a dark streak without any known trauma, or if the streak gets bigger or changes shape, it’s important to get it checked by a dermatologist. This streak may also have an ill-defined border and can multiply or spread.

Another symptom to watch for is when the nail starts lifting or separating from the skin underneath (the nail bed). This can make the nail look like it’s coming off or peeling away. Nail separation is often painless in the beginning, but can become uncomfortable or painful as the cancer progresses. This symptom is often overlooked because people may think their nail is simply damaged or infected as a result of some injury. However, persistent nail lifting without an obvious cause should raise concern and prompt a medical evaluation.

Nail cancer can cause general discoloration of the nail, such as black, brown, or even red hues. Sometimes the skin around the nail may also darken or show pigmentation changes, a warning sign known as Hutchinson’s sign. This means the pigment extends beyond the nail onto the adjacent skin. Darkening or unusual color changes in or around the nail can be subtle and easily missed, especially in people with naturally darker skin tones. If you notice any new or unusual color changes that do not go away, it’s important to seek medical advice.

Nail cancer can cause the nail to become thinned, cracked, split, or distorted. The nail plate (the hard part of the nail) may look irregular or damaged. Sometimes the nail develops dents, and it may stop growing normally altogether. These changes are often mistaken for fungal infections or trauma, but if they persist or worsen without treatment, they could indicate cancer. Nail deformities combined with other symptoms like discoloration or pain should be evaluated by a healthcare professional.

As nail cancer advances, you might notice bleeding under the nail, formation of ulcers, or small lumps (nodules) beneath the nail plate. These symptoms indicate that the cancer is affecting deeper tissues and causing damage.
Bleeding or ulcers under the nail is not common otherwise, and can be painful and may not heal easily. Nodules or bumps can sometimes lift the nail or cause discomfort. These signs are serious and require immediate medical attention.

Sources:
Moffitt Cancer Center – Subungual Melanoma
American Academy of Dermatology – Nail Melanoma Signs
US Dermatology Partners – Nail Melanoma Symptoms
Cleveland Clinic – Nail Cancer Signs

Disclaimer: This article is informational only and not a substitute for medical advice. Always consult a medical professional if you spot any nail changes