500ccs or 550ccs? (Photo)

Thank you for your question and photos.  There is minimal difference between the two such that one may not even perceive any difference.  One needs to evaluate the tissues to determine what your body can tolerate.  I would start with a face to face consult with a Board
Certified Plastic Surgeon who has experience in breast surgery. During your
visit your surgeon should be evaluating your health to determine if you are a
good surgical candidate and examining your tissues to get a sense of what type
of procedure your tissues will allow. Only with a hands on exam can this be determined.
During the consult you and the surgeon should be understanding of the goals and
realistic outcomes of your choices. Once an exam and opinion is rendered then
you can decide if surgery is right for you. Good luck.

A 500 cc implant is a large implant for your size. I would suggest going back to your surgeon and discussing sizes again. If possible, try on a 500 cc sizer so you can feel the weight and get an idea about the size. I do not recommend going past the size that best suites your frame and what your tissue will support.