Hard Knots in Lower Back? (back mice)

Hard Knots in Lower Back?

Recently, and thanks to an email from one patient, I have realized that the fact that back mice are so UNKNWON by the medical community, even nowadays, makes the search for information about them a hard task. When patients and even doctors try to search information about the nodules by googling, they have to describe them in many different ways, as best they can.

Since in most of the cases we don’t know a proper “medical” term to search information about these intriguing painful nodules, people use several descriptions such as: hard knots in lower back, painful nodules in the lower back, painful lumps in low back, painful fatty lumps, and painful lumbar lipoma, among others.

This reminds me of my own experience, back in the summer of 2017 when I was trying to find out about these mysterious painful knots in the back because my husband started complaining about backache. Although I am a doctor myself, I had to use these descriptions to find a hint about what they could be. My first attempt was to type the words bultos dolorosos en la espalda (painful lumps in the back), and hope to find information about these nodules on the net. At the beginning, this search led me to some blogs about chiropractic massage that included some medical references and, since then, I have found many more medical articles, and that’s why I am sharing this useful information in this web page.

The fact that there are so many names to describe this entity shows that it is still really unknown, and every person that discovers them gives them a different name: edematized subfascial fat herniation, fibrositis of the back, episacroiliac lipoma, sacroiliac lipoma, cellulite nodule, xanthoadipose nodules,   nodolo di Copeman, fibro-fatty nodule, hernia del panniculo adiposo, BACK MOUSE OR MICE…

Hard Knots in Lower Back?

The purpose of this web page is providing both doctors and patients with relevant medical information in a clear way. We hope it helps to move forward!

Published in January 2019 by Marta Cañis Parera

21 Replies to “Hard Knots in Lower Back? (back mice)”

  1. My wife has had her back mouse needled twice but after playing golf her symptoms have returned.
    We live 6/12 in Catalonia
    Do you have a clinical practice?

  2. Hello,
    Are you aware of any doctors in the Boston area who are familiar with back mice? I’ve had a mostly painless movable nodule to the left of the small of my back for over twenty years (at the dimple.) It was diagnosed as a lipoma many years ago and I was told it was nothing to worry about. I developed lower back pain around the same time which has never resolved completely with typical treatments. It wasn’t until recently, after countless theories and a number of rounds of PT as well as regular chiropractic treatment, that occurred to me that perhaps the “lipoma” and back issues are related. I’d love to find someone in the Boston area who recognizes back mice as a possible cause of chronic back pain. Any assistance is appreciated.

    1. Hello Janice,

      Unfortunately I do not know a specific doctor from Boston. Did you notice that when you press upon it, they are o become painful?

      You can ask your doctor to do a simple test with a local anesthetic injection on it. If pain resolves (sometimes it is just hours, sometimes longer) then it means the mouse can be the trouble.

      You can show your doctor the list of recent medical articles that explain about back mice. Maybe then they will better understand it.

      Best wishes,

  3. Hi,

    I had these removed a few years ago. They grew back! They seem to be the cause of relentless, chronic pain for over 6 years now.

    I’m in the midwest and open to any doctor who knows what these even are!

    1. Hi Tara,
      We are currently studying the nodules. Some past medical studies referred that in some cases (not always), after surgical removal, the nodules form again within years. Did you try to manage them with anesthetic blocks, to start?

  4. I was curious if your own study or others indicated whether patient weight loss would affect the back mice. If a patient lost a significant amount of weight, are back mice reduced in size? Or, are they currently padded/protected by fat, and a loss of surrounding fat would make the matter worse?

    Any thoughts or ideas you had would be most welcome.

    1. Hello Brian, good question!

      In general, the studies do not mention the weight loss as a treatment. They do mention that a healthy diet, exercise and good living and working conditions are important to prevent “back mice”.

      There is an old article from a Stockman, a known researcher that did put on diet a patient that presented a general condition “like a mice infestation” called Dercum’s disease – they present multiple painful nodules in many locations including the lumbar zone-.

      Stockman R. The Clinical Symptoms and Treatment of Chronic Subcutaneous Fibrosis. British Medical Journal. 1911;1(2616):352-355.
      direct link: //www.ncbi.nlm.nih.gov/pmc/articles/PMC2332909/

      I have noticed that the back mice are usually small in slim patients and bigger in obese patients, but they can be painful anyway.

      I would guess that a Non-fatty hipocaloric diet could have an effect on the fatty deposit tissue, but it needs to be studied.

      What are your thoughts?


  5. Hello, what is the best type of imaging to diagnose lipomas in/near spine and/or SI joint?

    I’ve had nearly 3 years of back pain, and I know I have two herniated discs, but a general dr recently identified at least one lipoma in my lower back in area of pain (he called it angiolipoma since it is painful). He also noted several more on my legs, including one on my hamstring I have thought for 7 years was scar tissue/muscle knot which my massage therapist has worked on. Now I know why it never goes away!

    I have an appt w a neurosurgeon soon and would like to ask him to do an MRI w contrast or whatever type of imaging may best identify if I have other lipomas that could be causing my pain. I don’t want to have disc surgery if there is an underlying lipoma that would still be an issue.

    Thanks, Leslie

    1. Hello Leslie,

      This web page focus with a clinical entity called “back mice” or “episacroiliac lipoma”. These are painful fibro-fatty nodules that can be palpated in the subcutaneous tissue in low back. The best way to diagnose them is by ultrasound. They are “invisible” in MRI. Intra-nodular anesthetic injection can help to know if they are the cause of your low back pain. There are other types of lipomas. So maybe yours are not really “back mice”.

      Show your doctor the recent medical articles in this list:

      Best wishes,

  6. Hi, I’m very interested in the topic.
    Are you aware of any doctors in Italy who are familiar with back mice? I need this info for my brother, who has a three years history of back pain: same symptoms described here, no medication worked, job problems… nothing detectable at MRI, a nodule at ultrasound. He had a local injection and the pain decreased.
    I need to find a doctor to solve definitively his pain, also with surgical treatment.

    1. Hello Patrizia,

      Sorry, I personally do not know any doctor.
      This is the latest Italian article I could found about the subject (1970)


      In Italian wikipedia article they called “Nodulo di Copeman” (Copeman was a known English medical doctor that studied them)


      The best you could do is find an open mind doctor that is willing at least to read the latest medical articles, here there are some of the articles (I could send you them by pdf if it is useful to you).


      Best wishes,
      Marta Cañis

  7. I know this is what I have. I have lipomas all around my body. Since 2/14/18 I have had chronic low back pain. It wraps around to my front and to the uterus. It feels like contractions like I’m in labor. If I do anything laundry, stand doing dishes to long walk to long it will trigger the pain. What has puzzled primary, chiro, gyn, neuro is that I will spot when I get the pain. So they don’t see how it’s all connected. I think it could be inflamed or something and I have fibroids in my uterus maybe idk but I have a lipoma in my right low back that starts the pain. Thank you I’m gonna go over this with my doctor Monday.

  8. Hi! I have a back mouse on the right side of my back; could this in any way be causing my right gluteal muscle to fasciculate? Doctors here in NY are so perplexed by this random fasciculation/spasm!


    1. Hi Kjain0633! I am Marta Cañis Parera. I can not help you with your question. The medical articles that I studied do not mention the ‘fasciculation’ as a clinical finding -related to back mice.

      Best regards,

        1. Hello Knika Singh,

          Probably back mice are not visible in MRI because they are formed by ‘abnormal fibrofatty tissue overgrowths maybe herniated’ that are seen in the MRI exactly the same ‘colour and texture’that the surrounding ‘normal fibrofatty tissue’.

          Best regards,

  9. I’ve had back mice for many years but never knew what they were. They caused a lot of pain–especially pressed against the seat while driving. In 2016 I went from my dermatologist to my general practitioner to pain management Drs and all agreed they weren’t regular lipomas but no one knew what they were so no one would treat me. I did my own research and found a study that they were back mice and could be treated by being punctured with a needle six to eight times. I took the study into pain management and they agreed to do it. I no longer have tender pain when the lumps are touched. I developed a new one last week that was very painful and had back spasms for days. Yesterday I used anesthetic cream (& all done very sterile!) my husband poked it about eight times with a 22 gauge syringe. Today it doesn’t hurt at all! By the way, if you’re interested I am of a normal weight, but I do have Ehlers Danlos syndrome so I just figure my connective tissue isn’t strong enough to keep my fat in. Thank you for all the information you’ve posted. When I researched it in 2016 there was almost nothing online!

    1. Hello Stephanie D,

      Thanks for your words. Thanks for sharing your case. Specially the fact of your Ehlers Danlos syndrome.

      Take care!
      Best wishes,

      Marta Cañis Parera

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