Far lateral extraforaminal lumbar synovial cyst: report of two cases.
OBJECTIVE
We present two cases of a far lateral extraforaminal synovial cyst at the L5-S1 level of the spine. Neither case was diagnosed as a synovial cyst before surgery because of their atypical location. Only one other case of an extraforaminal synovial cyst, located at L4-L5, has been reported in the literature.


METHODS
Both women presented with radicular leg pain and examination findings consistent with L5 root compression.


METHODS
During surgery, the cyst was not associated with the facet joint. One cyst was adherent to the nerve root. Both cysts were completely resected, with excellent pain relief.


CONCLUSIONS
These cases serve as a stimulus to look outside the spinal canal and foramen in patients with symptoms suggesting nerve root compression. Far lateral extraforaminal synovial cyst should be included in the differential diagnosis.
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
Loi K
LK
Phuong
John L D
JL
Atkinson
Kent R
KR
Thielen
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D010166:Palliative Care; D013122:Spinal Diseases / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D013581:Synovial Cyst / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*