Skin Cancer Symptoms

This article describes the common symptoms that might indicate the presence of melanoma.  Melanoma is an important cancer to be aware of and to know what the symptoms or signs of it may be.  Melanoma is a type of skin cancer.  It only accounts for about 4% of all skins cancers but causes the vast majority of deaths from skin cancer.  Melanoma is relatively rare.  Each year there are about 60,000 diagnoses of melanoma however it remains in the top ten causes of death from cancer for both men and women in the United States. 

An important part of understanding the symptoms of melanoma is to know who is at risk for this.  Melanoma could theoretically occur in anyone however there are several well established risk factors that make its occurrence more likely.  Risk factors for melanoma include:

  • Sun Exposure
  • Ultraviolet Radiation (particularly UVB type, from sun exposure and tanning beds)
  • Fair Skin
  • Men > women
  • Congenital nevi (a precursor skin lesion)
  • Previous non-melanoma skin cancers (such as  basal cell or squamous cell cancers)

There are several different types of melanoma and they rarely occur in places other than the skin.  Greater than 90% of melanomas are found on the skin.  About 5% of melanomas arise on the eye.  Different types of melanoma include superficial spreading, lentigo, acral, and nodular.

The key to effective treatment of melanoma is early recognition.  The reason this is so important is because melanoma tends to be an aggressive cancer and has a tendency to spread to other places in the body.  When a cancer spreads this is called metastatic disease.  There is not really any effective chemotherapy or non-surgical treatment that will consistently result in cure or good long term outcomes for melanoma.  Thus, removal at the earliest possible stage provides the best chance for cure and good long-term outcome.

The important features that signify a potential problem with a mole have been described conveniently as ABCDE.

  • A – Asymmetry: Any mole with an asymmetric outline is more concerning than an entirely symmetric circle or oval type lesion.  The typical picture of a cutaneous melanoma shows dark coloration and jagged edges.
  • B – Borders: Irregular borders are a concerning feature for any mole.  Similar to symmetry as mentioned above, irregular moles or dark skin spots with jagged edges are more concerning for possible melanoma.
  • C – Color: Changes in color or variation in color across the skin lesion.  A melanoma is more likely to have asymmetry in the coloring of the lesion.  Part of the mole or skin spot may appear black with an adjacent area being gray or brown.  A symmetric, consistently colored skin lesion with smooth edges is much less concerning then an asymmetric larger mole with color variation.
  • D – Diameter: Larger skin lesions are more concerning for skin cancer.  The threshold for concern is 6 mm or about the diameter of a pencil eraser.  An irregular, dark skin lesion with patchy coloration that is larger than 6 mm would be quite concerning for a melanoma.
  • E – Elevation: Skin cancers tend to grow in all planes.  A mole with raised parts to it, particularly if they are irregular and not symmetric, is more concerning for melanoma.

In addition to the convenient “ABCDE” mnemonic, other signs of melanoma include a mole that begins to change or one that seems to ulcerate and bleed.  Any skin lesion that bleeds or begins to change color, shape or size should be brought to the attention of your doctor.  If there are swollen or firm lymph nodes near the area of melanoma, this is concerning for possible spread to the nearby lymph nodes.  The lymphatic system drains into regional lymph node basins.  For example, a cancer of the right arm will usually spread to lymph nodes in the right armpit.

A particularly difficult scenario is someone who has many freckles, numerous sun spots or pigmented areas of the skin.  It is impossible and impractical to biopsy a hundred skin lesions.  In these scenarios the best strategy involves taking a sample of the most concerning area and taking routine photos of the remaining ones.  Doing this in conjunction with frequent Dermatologist visits is important for long term follow-up.

Someone who has the above risk factors and a skin lesion with any of the above red flag warning signs should get immediate examination and evaluation by a physician.  The typical evaluation of a very concerning skin lesion will involve some type of sampling of the cells to see if they contain cancer.  The method of cell sampling varies depending on the size of the lesion and where it is.  One of the most common ways to biopsy a concerning mole is called a punch biopsy.  This involves taking a core of tissue with a circular blade about the size of a pencil eraser.  This can then be examined under a microscope for evidence of melanoma.  If melanoma is found then a wider area needs to be removed to ensure all the cancer is gone.  The other part of the process involves checking to see if there is evidence that the melanoma has spread to anywhere else in the body.  There are a variety of special tests and x-rays that can accomplish this further staging.


  1. Townsend Jr, CM; Beauchamp RD; Evers BM; Mattox KL. (2008) Townsend: Sabiston Textbook of Surgery, 18th ed.  Chapter 30.  New York, NY: Saunders.
  4. This article was originally published on September 3, 2012 and last revision and update was 9/4/2015.