Hi, thanks for writing to HCM.
From your description of symptoms, a possibility of skin cancer
in your case in unlikely.
Propably it could be an ALLERGIC REACTION
to an unknown sting or bite.
Generally skin cancers develop in areas of skin exposed to sunlight (though there are exceptions).
You should approach your treating doctors when you see any of the following symptoms / signs in a lesion -
* rapid increase in the size of lesion
* change in the color of the lesion
* when a lesion bleeds to touch
* any change in the consistency (feel)
Hope this information is helpful. Good day