The "moveable" lumps in the low back region around the hip area are called Back Mice, they have other official names. While the lumps occur in 10% of the population, only about 10% of those who have them get pain from them. The pain can mimic herniated disc and sciatica type pain. Because of this mimicking, the cause of pain is often misdiagnosed and is also the reason they are so little known. The reason they CAN hurt is this, they often are caused by some traumatic event, like an auto accident, labor, etc. The fatty tissue in the sacroiliac region of the low back breaks through the membrane and is trapped between the skin and muscle. This fat nodule (back mouse) SOMETIMES carries nerves with it and because of the pressure it causes to the nerve, pain is produced. Very few doctors know about these things. Most of the articles about them online are posted by massage therapist and acupuncturists.
I had an auto accident in 1999 and for 13 years I've dealt with horrible chronic low back pain on my left side. I have two of these lumps and no matter how many doctors, surgeons and other specialist I complained to about them relating to my pain, they all said they were not the cause of the pain. It was an acupuncturist/massage therapist I recently visited for three months to try and "work" these lumps out that said I needed to find someone who will take a look at them. She was unable to work them out and agreed with me that they were the cause of my pain.
So I searched online (Nov 2012) and found some articles on back mice. They all pointed to a Dr. Peter Curtis MD. They can be cured relatively easily by injection therapy or removal. In most cases the pain will be gone immediately after injection therapy, if done correctly, but some may need to be removed. Before I found the article below on the injection therapy technique, I read in forums that they shot anesthetic into them. So I told my doctor to just shoot something into them to see if anything would happen. He did a single shot of anesthetic into each nodule and I immediately felt the sciatica in my leg and the awful stabbing pain that never goes away, go away! After 13 years of pain and Methadone/Percocet, I felt wonderful. It only lasted about 18 hours but it showed me they were the cause of my pain. As mentioned after this I found this article explaining how to do MULTIPLE injections into the lumps to bring immediate, long lasting, if not permanent relief from pain. I emailed my doctor the article and am I'm making an appointment to have the injection therapy done next.
The procedure for injection therapy is explained in the FULL article. I could not find the full article on line, I had to get it from a library. Here's an excerpt from the article that is found online.
Treatment of Low Back Pain Associated with "Back Mice" A Case Series.
Motyka, Thomas M.; Howes, Barry R.; Gwyther, Robert E.; Curtis, Peter
[Article] JCR: Journal of Clinical Rheumatology. 6(3):136-141, June 2000.
(Format: HTML, PDF)
Back mice are subcutaneous fibroadenomatous nodules that cause low back symptoms. Previous case reports do not provide systematic descriptions of the clinical presentation or long-term follow-up of this problem. This retrospective case series reports syndrome characteristics and treatment outcomes for injection therapy for "back mice." We completed telephone interviews, chart reviews, and written questionnaires for a convenience sample of 35 participants.
Participants reported the following symptoms: pain radiating to the lower leg (37%), leg numbness or paresthesias (14%), and a median of 8 weeks of pain before treatment (range 3 weeks to 10 years). Thirty-one participants (89%) received lasting relief from injection of local anesthetic and corticosteroid. Injection therapy relieved both local and radiating symptoms but often did not eliminate the nodules. Thirty participants (86%) were "satisfied" or "very satisfied" with the treatment. There were no adverse events reported.
Back mice can cause radiating pain that can be confused with other low back or leg syndromes. Injection treatment seems to be effective, long lasting, and well tolerated. Physicians should search for these nodules in patients with unexplained low back pain and try injection therapy before initiating expensive therapy.