Pain 3 years later after lipoma removal. Path report shows nerves in lipoma

[11RN]

I am a nurse and I have a question for my sister. First some backstory. 2013 she rapidly developed severe right lower back pain. The docs couldn't find a cause. For a year she saw physical therapy, had injections etc. She had at that same time developed what they thought were lipomas on her right lower back a few inches from the base of her spine. After a year she convinced a general surgeon to remove the lipomas (they were deep) and had instant relief from her pain. In 2016 the pain came back. They found another deep tumor in the same area and she had surgery again. However this time she had excruciating pain upon waking from surgery and has really not gotten any better. At first they blamed a rather large seroma she developed post op, but the pain only very mildly relieved once it resolved. That the best relief she had was after the doctor had drained the seroma some and then injected lidocaine directly into the cavity. Doctors moved on, apparently deciding the lipomas weren't to blame. Another new symptom was numbness over her right buttock and down the back of her thigh. In the past three years she had a fusion done for a very small herniated disc, and a nerve stimulator placed to her spine with little relief. She's on disability but was just turned down for Social Security disability because they say there is nothing physically that could be causing the pain. I was up visiting and helping her sort through her medical records this weekend for her appeal and found the pathology reports for both lipomas. One has regular fatty tissue, but the other had focally entrapped nerves in the tissue. I can't find anything about lipoma is having nerve tissue in them. Could it be she had a neuroma instead of a regular lipoma and suffered some nerve damage? Or maybe the surgeon cut nervous tissue he shouldn't have?