Does Melanoma Always Appear as an Atypical Mole? 

May 02, 2024
Does Melanoma Always Appear as an Atypical Mole? 
You’ve heard that atypical moles are a common starting point for melanoma, the most aggressive and deadliest form of skin cancer. While that’s true, it’s also true that melanoma doesn’t always get its start in a changing mole. Learn more here. 

Every year in the US, more people are diagnosed with skin cancer than all other forms of cancer combined. Skin cancer is so common that over 9,500 Americans learn they have it every day — and one in five adults develop it by the age of 70. 

Experts estimate that melanoma, the fastest-growing and most aggressive form of skin cancer, will account for over 200,000 new skin cancer cases in 2024.   

This May, in recognition of Melanoma and Skin Cancer Awareness Month, our board-certified dermatologists at Florida Dermatology Associates are here to provide insight into this deadly disease — including the common misconception that it always appears as an atypical mole.    

A short tutorial on skin cancer

Most skin cancer cases — about 90%, according to experts — happen when exposure to damaging ultraviolet (UV) light rays (either from the sun, tanning bed use, or both) causes a genetic mutation in skin cell DNA that leads to errors in the dividing and copying process that drives ongoing skin regeneration.   

These damage-prompted, mutation-fueled errors can give rise to the emergence of an abnormal, uncontrolled growth or lesion called skin cancer. While malignant skin growths get classified by the type of cells they arise from, all skin cancers fall into two general categories: 


Nonmelanomas account for most skin cancer cases, affecting over five million Americans every year. Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), the two most diagnosed skin cancers, are less likely to spread beyond the skin because they grow slowly. 

While it’s important to recognize that 5,400 people worldwide die of nonmelanoma skin cancers every month, they’re also highly treatable with early detection and care. If caught early, nonmelanoma skin cancers have a five-year survival rate of 99-100%. 


Melanoma is the least common skin cancer diagnosis, but it’s also the most dangerous one. Of the 200,000 new melanoma cases expected this year, half will be noninvasive or confined to the outer layer of skin (epidermis), and half will be invasive, penetrating the second skin layer (dermis).  

Melanoma, the “black tumor”

Melanoma is derived from the Greek words “melas” and “oma,” meaning black tumor. Melanoma cancers grow from melanocytes, the pigment-producing cells that give your skin — and your moles, hair, and eyes — their color.  

Melanoma accounts for one in 100 skin cancer cases, but causes the highest rate of skin cancer deaths. Still, when caught and treated early, melanoma also has a five-year survival rate of 99%.  

Atypical moles and melanoma

The average adult has 10-40 common moles, which occur when melanocyte cells cluster together. A healthy mole may be flat or slightly raised, match your skin tone, or be colored a darker tan, brown, or black shade. 

An atypical mole, on the other hand, appears different from a normal mole. Atypical moles are worrisome because they can be a sign of melanoma, and even if they’re not melanoma, they have an increased propensity to grow melanoma.  

You can boost your odds of catching melanoma early by getting to know the ABCDEs of atypical mole identification

  • Asymmetry: one half doesn’t mirror the other
  • Border: uneven, jagged, or poorly defined borders
  • Color: has more than one color tone
  • Diameter: bigger than the size of a pencil eraser 
  • Evolution: rapid changes in size, color, or shape

About one-third of melanoma skin cancers begin in atypical moles. These may be normal moles that change and become atypical or atypical moles that change over time. Anyone with atypical moles should routinely monitor them for changes. 

Melanoma can start anywhere  

Atypical moles may be synonymous with melanoma, but that’s just part of the picture. In reality, more than two-thirds of melanomas do not begin in atypical moles; they emerge on unmarked skin areas. 

Melanoma can appear as a scaly patch of thick skin, an open sore that bleeds, or a raised, dome-shaped growth that feels firm. It can also emerge as a dark vertical line beneath a fingernail or toenail or as a band of darker skin around a fingernail or toenail. 

Sometimes, these dangerous malignancies emerge as a new age spot, freckle, or mole that appears suddenly, quickly grows, and looks different from other spots. Melanomas can also start in other pigmented tissues, such as the iris of your eye.  

Are you at risk of melanoma?

Your melanoma risk is higher if you have many moles — or at least four atypical moles. The bottom line? You can reduce your melanoma risk by knowing your skin, performing regular skin self-exams, giving us a call when you notice something unusual, and staying on top of annual skin cancer screenings.  

Are you concerned about skin cancer? Call your nearest Florida Dermatology Associates office in Palm Bay, Cocoa Beach, Cocoa, Melbourne, Titusville, or Rockledge, Florida, today, or click online to book an appointment