It would be impossible to tell what these are without a doctor to see them firsthand. One guess is that they may be liver or age spots. These spots are most commonly found on the backs of hands, tops of feet, face, shoulders and upper back.
Our expert, Sue Chung, has written an article about how to get rid of brown spots that you may want to read for advice.
The main thing is...you want to make sure that these are just age spots and not melanomas. So I do strongly suggest that you see your doctor or dermatologist just to make sure.
Hope this helps some. Thank you for your question.