Dermatology Image Atlas; if you're looking for pictures.....
 

I have 3 bright red "blotches" in one armpit. I searched this site looking for a description of what skin mets look like. Some people used good descriptors, but without a picture, it is much harder to know what skin mets really look like.

Complicating the issue is the fact that these metastisis have an asssortment of visual clues. Some have nodules, some are more "rashy."

I thought this was a good site that shows a large assortment of skin disorders. Breast cancer is also listed.

http://dermatlas.med.jhmi.edu/derm/

Click on "Index."

Where was it? That's a HUGE list

Yes, it was a big list, but I found it helpful. For my particular situation, I found applicable pictures for "axilla (armpit.)" It seemed especially difficult to find pictures on the internet that show pictures of skin metastasis.

Under the "Diagnosis" column, go down to "Carcinoma, Breast."

Under "Body Sites," "Breast" is also listed, but that pertains to a large assortment of skin problems that can occur on the breast itself.