Can you post a photo? The only way to remove lipoma's is through surgery. However, I REALLY don't think you have a lipoma.
When someone looses a large amount of weight, like you did, the weight loss usually isn't evenly distributed throughout the body and often there are small pockets of stubborn fat.
There isn't much you can really do about it. They will be burned eventually. You just need to keep loosing body fat. A good topical fat burner like yohiflame from n2bm.com will help liberate the fatty acids from your stubborn body part areas. I would add yohiflame to the areas before and after workouts and cardio sessions.