Is it a Bruise or maybe Subungual Melanoma

Let’s talk about something important –Subungual Melanoma, or SM for short. SM is a type of malignant (cancerous) melanoma that occurs in the nails. Unlike melanoma on the skin, it is not caused by sun exposure. Instead, hurting your fingernails and toenails repeatedly increases your risk of developing SM.  

You might notice SM when your nails start to change colour, usually brown or black. As it gets worse, your nail can start to hurt and might even be destroyed, which is typically quite painful. The main way to treat SM is to remove it with surgery. How deep they have to cut depends on how far the SM has grown.  

 The earlier we can find and treat SM, the better it is for the patient’s outcome. When SM is diagnosed at Stage 1A, there’s a good chance of surviving beyond 5 years – about 97% chance! But if SM is diagnosed at Stage 4, the chance of surviving beyond 5 years is only about 15-20%. 

To find SM early, doctors use something called the ABCDEF guidelines. Yearly screenings are still the most effective method for clinicians to diagnose SM at an early state, leading to improved patient outcomes.  

Now, you might be wondering how to spot SM. Because finding SM early makes a big difference, knowing the signs and telling SM apart from other nail problems is really important. 

What does SM look like? 

 SM usually shows up as a black-brown streak or a strange colour on your nail bed. Here’s more about it: 

• In most cases (75-90%), SM develops on the big toe or thumb.  
• It often makes the nail look brown or black 
• Sometimes, you might see a dark, up-and-down stripe on your fingernails or toenails.
• As it worsens, it can make your nail bed thick, painful, split, and damaged. 
  

The Hutchinson Sign 

The Hutchinson sign is a potential clue that someone might have SM. It shows up as an extension of brown-black colour near or on the fingernail or toenail. While this sign is valuable, it is not always a surefire way to tell if someone has melanoma. 

What Can SM Be Mistaken For? 

Sometimes, SM can look like other skin conditions, resulting in a delayed diagnosis and worse health outcomes. The information below can be helpful to consider when evaluating suspicious nail lesions. Still, it’s best to see a physician immediately if you notice anything unusual or concerning on your nails. Here are a few skin conditions SM is often mistaken for: 

• Longitudinal Melanonychia (LM) LM presents itself as tan, brown, or black lines running from the bottom of your nail near your cuticle to the tip.LM always develops before the age of 50. The misdiagnosis of SM for LM results in a delayed SM diagnosis and poorer outcomes. Follow up on lesions appearing as LM for changes over time as these may indicate SM
  
• Onychomycosis is a fungus that infects nails, often your toenails, and causes them to change colour, become thicker, look strange, and even come off from the nail bed.
  
• Subungual Squamous Cell Carcinoma (SSCC) SSCC has a wide variety of way it presents itself on nails and skin including pain, sores, thicker skin on the outside called hyperkeratosis, rough nails with lines or ridges called nodular trachyonychia, dark lines on the nails called longitudinal melanonychia (LM), or red streaks in the nail called erythronychia.
  

Differentiating SM and Nail Trauma 

SM can often be mistaken for a bruise, also known as subungual hematoma, which can result from nail trauma. But recognizing key differences between SM and nail trauma can guide you in deciding when to consult a physician for an assessment.  

Nail trauma can take on different appearances based on how the injury happened. Generally, nail trauma shows up as a blue-black, reddish, or purple discolouration affecting either the entire or part of the nail.