Warning Signs of Skin Cancer

Our skin reflects a lot of our overall health. Dr. Khanh Truong and Dr. Henry DeGroot, of NorCal Dermatology in Santa Rosa, CA, would like to help you keep your skin healthy and identify warning signs of skin cancer that you shouldn’t ignore.

What Are Warning Signs of Skin Cancer?

Cancer is the rapid, often irregular, reproduction of cells. Because of this, it is easy to think that it should be easy to spot because it would be a consistent result. This is far from true. Be mindful to watch for these warning signs.


Moles are abnormal growths of skin cells with a root beneath the surface, but they are not technically cancerous and do not spread to other organs. 

There is an ABCDE process to help to monitor and evaluate the risk of moles to be cancer:

  1. Asymmetry - one part of the mole doesn’t match the rest of it;
  2. Border - the outside edge is irregular;
  3. Color - the color is not the consistent;
  4. Diameter - it is ¼ of an inch, larger, or growing;
  5. Evolving - it is changing shape, color, or size.


Freckles are a light discoloration of the skin, often getting worse with exposure to sun. These are usually harmless and tend to be genetic. However, the same ABCDE for moles can apply to freckles.

Skin Tags

Skin tags form for similar reasons as moles, but form on the surface with no deeper roots. They are generally harmless and highly hereditary, but random formations can indicate problems beneath the surface.


There is a lot that happens beneath the surface of the skin. Clogged pores (usually acne or ingrown hairs) are the most common reason for bumps to form. However, these lumps can be an indication of cells lumping together rather than oil or hair blocking a pore.

Random Discoloration

Our skin tends to be uniform in color, with there being slight differences for certain areas of the body. The bottom of the arms is usually lighter than the top. But, a small area of skin being noticeably lighter or darker than the rest of the area can indicate something unusual occurring in that area.


Though freckles and moles may be entirely benign in your genetic lineage, they should be pretty uniform. If you have a solitary freckle that is a different color than the rest, this may warrant some attention.

If you are in the Santa Rosa, CA area and have concerns about something on your skin, call (707) 527-9517 to schedule a consultation with the professionals at NorCal Dermatology so that Dr. Troung and Dr. DeGroot can help you get some answers.

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