The extraforaminal juxtafacet cyst as a rare cause of L5 radiculopathy: a case report.

STUDY DESIGN This is a report of a case. OBJECTIVE To document the clinical, radiographic, and histologic characteristics of a lumbar extraforaminal juxtafacet cyst. SUMMARY OF BACKGROUND DATA Spinal juxtafacet cysts develop most frequently at the dorsal aspect of the zygapophysial joint, sometimes in the posterolateral area of the canal. In one case, they have been described in the foraminal and extraforaminal region. METHODS Description of the case report. RESULT The authors report one case of a strictly extraforaminal juxtafacet cyst responsible for L5 sciatica. CONCLUSIONS Juxtafacet cysts of the spine represent an infrequent cause of sciatica, usually when they grow in the canal, or more exceptionally when they occupy the foraminal or extraforaminal areas.