Skin Cancer or Breast Cancer? How to Tell the Difference

This week I had a sweet, older man who came to see me for eczema on his arm and lower back. His internist had been treating the spots as eczema for four years. All the while, the eczema seemed to be getting a little bit better in the middle of one of the spots and then would get worse and spread. This was not eczema, it was a type of squamous cell carcinoma skin cancer called Bowen’s Disease.

Another patient, a forty-something year-old woman had a new, scaly patch covering her nipple. It too was a type of skin cancer; a breast cancer called Pagent Dsease that can often manifest as a scaly pink rash in or on the breast. This is always a conundrum to the inexperienced eye and can easily be confused for a benign case of eczema.

It can be easy to confuse skin cancer for eczema.

These cases brings back to my mind a man whom I saw during an oncology rotation years ago as a third year medical student. I didn’t know much about dermatology at the time, and yet, I knew there was something not quite right about his patch of eczema. In this case, the man who was undergoing treatment for rectal cancer also had a humongous pink, scaly plaque on his abdomen that measured about seven by seven inches. As we left the patient’s room one day, the oncologist with whom I was working just mentioned “oh, that is just a patch of eczema” and continued out of the room.

In my third year med student ignorance, I stepped out on a limb and posited that perhaps this was skin cancer because something back then told me that it just didn’t look quite like eczema.

Now, years later and after practicing dermatology for ten years, I have the opportunity to hopefully help someone to catch their skin cancer or breast cancer very early in the game.

How to Tell The Difference

1. You can tell the difference between skin cancer and eczema often by the distribution; eczema has a very typical distribution usually on the folds of the skin, the hands, feet, trunk, and lower legs. It will come and go and is very itchy.
2. Eczema, skin cancer and breast cancer can all bleed when the skin is scratched. Skin cancer and breast cancer however, tends to bleed if you even slightly scratch them. We call this friable skin. The skin bleeds very easily even with minor friction. The skin tends to be more painful in cancer as well.
3. Skin cancer, eczema, and breast cancer may all appear to improve (albeit temporarily in the case of skin and breast cancer) when they are treated with a steroid.
4. Skin cancer can have the appearance of clearing in the center or around the edges sometimes. This is actually where the cancer is progressing underneath/inside the skin. Eczema does not do this. When eczema clears, usually the entire treated area improves simultaneously.
5. Eczema tends to get better and stay better when you take bleach baths and apply skin barrier optimizing moisturizers to it a few times a day. Skin cancer does not.
6. And finally, skin cancer is usually localized to a single area (or in a very few areas as in this case) and does not tend to cover an entire limb, or two limbs for that matter.