Migrating lumbar facet joint cysts.
OBJECTIVE
The majority of lumbar facet joint cysts (LFJCs) are located in the spinal canal, on the medial aspect of the facet joint with characteristic diagnostic features. When they migrate away from the joint of origin, they cause diagnostic problems.


METHODS
In a 7-year period we examined by computed tomography (CT) and magnetic resonance (MR) imaging five unusual cases of facet joint cysts which migrated from the facet joint of origin.


RESULTS
Three LFJCs were identified in the right S1 foramen, one in the right L5-S1 neural foramen and one in the left erector spinae and multifidus muscles between the levels of L2-L4 spinous process.


CONCLUSIONS
Awareness that spinal lesions identified at MRI and CT could be due to migrating facet joint cyst requires a high level of suspicion. The identification of the appositional contact of the cyst and the facet joint needs to be actively sought in the presence of degenerative facet joints.
Department of Radiology, Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, England, UK.
Francesco
F
Palmieri
Victor N
VN
Cassar-Pullicino
Radhesh K
RK
Lalam
Bernhard J
BJ
Tins
Prudencia N M
PN
Tyrrell
Iain W
IW
McCall
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012447:Sacrum / Q000000981:diagnostic imaging / Q000473:pathology; D013581:Synovial Cyst / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D021801:Zygapophyseal Joint / Q000473:pathology*