I received a shot of Demerol and Fennergin in my buttock when I went into labor more than 2 years ago. Approximately 2 months after receiving the shot, a small spot formed at the injection site. Over the years, the spot has rapidly grown. The spot is about the size of a tennis ball and there is another smaller spot underneath the big one that is the size of a quarter. I have noticed recently that the large spot is spreading. There is now an indented line forming from the large spot and going around my hip. I recently had a biopsy done and they confirmed that it is fat necrosis. I don't know what my doc. plans to do next. Some side effects I have had from this is loss of weight (15 lbs. in 2 months) and haywire periods (one every 2 weeks).