Definition – What is epidural lipomatosis?
Epidural lipomatosis is a tumor-like, diffuse proliferation of fat cells in the epidural space of the spinal acid. The epidural space, also known as the epidural space, is a cleft space in the area of the spinal meninges. It is located between the periosteum of the spinal canal (stratum periostale) and the spinal cord skin, the so-called dura mater.
This epidural space is filled by connective and fatty tissue and contains venous vascular plexuses. In adults, it ends at the level of the second sacral vertebra. Lipomatosis of the epidural space results from the transformation of connective tissue-producing cells (fibrocytes) into fat tissue-producing cells (lipocytes). Epidural lipomatosis, also known as spinal lipomatosis, is a very rare disease whose prevalence (occurrence in humans) is unknown.
Causes of epidural lipomatosis
The occurrence of epidural lipomatosis can have various causes. Often it occurs idiopathically, i.e. without a recognizable cause. Furthermore, a connection between overweight (obesity) and various previous diseases is observed.
These include, above all, diabetes mellitus and diseases in which steroid excess occurs. These are conditions in which increased amounts of cortisone-like hormones are released. Endocrine causes include diseases in which the body’s own release of these cortisone-like hormones is increased.
A possible cause is paraneoplastic ACTH secretion. The term paraneoplastic means that the hormones are produced in the context of a tumor disease. The hormone ACTH promotes the production of cortisone-like hormones.
Furthermore, epidural lipomatosis has also been observed in patients after organ transplantation. This is due to the fact that so-called corticosteroids are usually administered afterwards to suppress the immune system. This high dose of corticosteroids also leads to a steroid excess.
Diagnosis of epidural lipomatosis
The diagnosis of a spinal epidural lipomatosis is made by a targeted synopsis of the patient’s symptoms and complaints, possible triggering factors and the results of the examination. Pain, sensory and motor disturbances can provide indications of epidural lipomatosis, which can then be further narrowed down by specific examinations. Imaging of the spinal column can then reveal an increase in epidural fatty tissue.
The MRI examination is particularly suitable for this purpose. Furthermore, in some patients a change in nerve conduction velocity and abnormalities in the examination of the reflexes can be detected. The MRI examination is one of the imaging procedures that do not involve radiation exposure.
Soft tissues, such as connective and fatty tissue, but also muscles, can be assessed very well by MRI, which is why it is the method of choice in the case of epidural lipomatosis. Depending on the type of MRI image, the fatty tissue can appear very bright. This is known as hyperintensity in the MRI.
In the case of epidural lipomatosis, a hyperintense increase in fatty tissue is visible in the epidural space of the spinal cord. This proliferation is not encapsulated, unlike in the case of a lipoma, for example. Depending on the extent of proliferation, a constriction of the spinal cord or of the outgoing spinal nerves can also be seen.
All articles in this series:
