Even under the best of circumstances, about half of grafted fat does not survive long term. This dead fat liquefies, turns into oil cysts, and eventually is reabsorbed, leaving behind hard scar tissue and/or calcifications. (This is also why fat grafting for breast enhancement is neither natural nor advisable, IMHO--the scar tissue and calcifications can interfere with the mammographic detection of breast cancer. But that's another topic.)For BBL patients, even more of the fat dies if the grafted fat is simply injected in large blobs rather than careful multiple tiny tunnels designed to make maximum contact of the grafted cells with living tissue. Big globs of fat might look full and round initially, but the majority of pooly-placed fat will simply die, turning into the big zone of fat necrosis you describe.That is not to say your BBL surgeon was bad or used poor surgical technique, BUT it COULD mean that. Was s/he a "real" plastic surgeon certified by the American Board of Plastic Surgery, or some other "board?"Dead fat must either be reabsorbed over a very long period of time, or be surgically aspirated, removed, or otherwise treated, especially if it become infected, which yours fortunately does not appear to be by description.Other than wasting your money and causing the discomfort of sitting on a glob of dead fat until your body can reabsorb it dead cell by dead cell, fat necrosis is simply dead tissue inside your body. (That's why it takes so long to go away, and why even rotten surgeons can fool their BBL patients into thinking they had a good procedure--it somehow must be the patient's "fault" or that sometimes "the fat just melts on its own." By then they're gone with your money.)Unless your buttock cheek develops significant tenderness, redness, or drainage (these, along with fever and chills eventually, signify infection), then time will indeed make this better (but NOT back to "normal") over many months. If infection develops, then surgical intervention will be necessary.Probably not by the surgeon who caused this mess in the first place. Seek ABPS-certified plastic surgeons who actually have experience and expertise in this, not some self-proclaimed "expert" whose background has nothing to do with plastic surgery. Best wishes! Dr. Tholen
