Tarlov cyst

A.Prof Frank Gaillard and Dr Jeremy Jones et al.

Tarlov cysts, also called perineural cysts, are CSF filled dilatations of the nerve root sheath at the dorsal root ganglion (posterior nerve root sheath). These are type II spinal meningeal cysts that are, by definition, extradural but contain neural tissue.

They occur in ~5% of the population, more commonly in women.

They have been occasionally associated in patients with connective tissue disorders:

The prevalence and severity of symptoms in patients with Tarlov cysts is controversial. Traditionally, and still largely the dominant view, it has been believed that like other spinal meningeal cysts, most Tarlov cysts are incidentally found and are asymptomatic. In some patients it appears that Tarlov cysts are the cause of symptoms, such as perineal pain/discomfort or lower back pain or sphincter/sexual dysfunction 3. Large cysts may cause local pressure effect and remodel bones. However, symptoms don't appear to correlate well with size 2

While they are most common in the lower lumbar spine and in the sacrum, they can occur anywhere in the spine. 

Most Tarlov cysts appear as CSF intensity simple cystic structures closely related to sacral and lower lumbar nerves.The sacral foramina may be widened. Morphology can vary from a simple rounded cyst to a complex loculated cystic mass.

It was initially described by I M Tarlov in 1938 1.

Usually, the diagnosis is self-evident and no alternatives should be entertained. Occasionally appearances are atypical and possible differential considerations include:

Share article

Article information

rID: 10198
Tag: refs, spine
Synonyms or Alternate Spellings:
  • Tarlov cysts
  • Perineural cyst
  • Perineural cysts
  • Sacral perineural cyst

Support Radiopaedia and see fewer ads

Cases and figures

  • Case 1: STIR
    Drag here to reorder.
  • Case 1: T2
    Drag here to reorder.
  • Case 2: sagittal STIR
    Drag here to reorder.
  • Case 3
    Drag here to reorder.
  • Tarlov cyst
    Case 4
    Drag here to reorder.
  • Case 5
    Drag here to reorder.
  • Case 6
    Drag here to reorder.
  • High signal focal...
    Case 7
    Drag here to reorder.
  • Multiple average ...
    Case 8
    Drag here to reorder.
  • Case 9
    Drag here to reorder.
  • Case 10
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.