PAIN AND ORTHOPAEDICS · Health guide
What Is an Episacral Lipoma? Nodules Around the Lower Back
Assessment of the nodules around the lower back known as “back mice”: the cause of the palpable lump, its relationship to pain and the options for follow-up.
Updated: · General information
What is an episacral lipoma?
“Back mouse” is a name used for certain subcutaneous nodules felt in the lower back and around the pelvis. They may also be referred to by terms such as episacral lipoma. It should not be assumed that every palpable lump is of the same nature, or that it is the source of the back pain.
How is it distinguished from a disc herniation?
A subcutaneous nodule and a problem with the disc between the vertebrae are different structures. On examination, the characteristics of the lump and any neurological findings are assessed; ultrasound or another investigation is chosen where needed. Because the two conditions can coexist, feeling a nodule by hand does not exclude a disc herniation.
How is treatment decided?
The nature of the lump and its relationship to the symptoms are assessed first. The decision to monitor or to intervene follows from that. Not every nodule requires injection, device treatment or surgery. It cannot be guaranteed that any particular method will permanently eliminate the pain.
How is a palpable lump assessed?
This name, used for small subcutaneous nodules around the lower back, is not in itself a definitive diagnosis. How long the lump has been present, whether it is growing, how mobile it is and its relationship to pain are all examined. Not every episode of back pain should be attributed to a palpable nodule; other musculoskeletal or neurological causes must also be considered.
When should you seek review again?
A lump that is growing, becoming hard, feels tethered to the skin or changes in appearance requires reassessment. Where needed, ultrasound or the opinion of the relevant specialty is requested. Attempting to press, crush or inject the lump without examination is not appropriate.
Your questions
Patient information
Is an episacral lipoma the same as a disc herniation?
No. A lumbar disc herniation concerns the disc between the vertebrae, whereas the term “back mouse” is used for nodules felt beneath the skin.
Should every nodule be removed?
No. Its nature and its relationship to the symptoms are established first. The decision to monitor or intervene follows from the examination findings.
