Gynecomastia Crater/Nipple Sinking-in. Is This Edema? What Could This Be? (photo)

The other Real Self responders to your question have given you some great answers.  Unfortunately, only time will tell.  It is very possible that there is swelling around the nipple and scar tissue at the base of the nipple pulling it down.  Once the swelling (edema) resolves, you will have a better picture of what is going on. 

At this point, I would wear a compression garment day and night with some Reston foam inside to add extra pressure, and possibly even an ace wrap to squeeze out all residual edema.  In my practice, we use therapeutic ultrasound (the kind physical therapists use for sore muscles) which converts sound energy into heat bringing blood supply to the area and carrying away swelling and some nonviable cells.  With a little luck, your surgeon did a perfect job and the edema and scar tissue are giving you the picture you see right now.  Pressure, ultrasound, and some judicious injections of Corticosteroid at the base of the nipple may fix everything, but if it does not, corrective surgery is relatively simple, quick and uncomplicated.

It is too early to assess the outcome of the surgery.  In my experience, this tends to resolve or improve with time.  Good luck and be safe.John T.
Nguyen, MD, FACS, FICSDouble Board
Certified Plastic Surgeon

It may simply be some early scar tissue drawing the area inward. Definitely massage. if it gets real tight a steroid injection might help. Keep in touch with your surgeon.