Lumbar synovial cyst in an adolescent: case report

Background  Spinal extradural cysts are a rare cause of spinal cord or nerve root compression which tends to occur in the elderly but rarely reported in the under 20s. History  A 14-year-old girl with a 9-month history of left radicular pain was found to have an intraspinal cystic lesion causing radicular compression. MRI showed a 1.1-cm extradural cystic lesion with a low signal on T1 and high signal on T2-weighted images lying in the spinal canal at the L4 vertebral body level. The patient underwent an L4 hemi-laminectomy and excision of a synovial cyst, and the radicular pain completely regressed. Discussion  We discuss the pathogenesis, radiological techniques, and management of synovial cyst in a pediatric patient. Conclusion  Intraspinal ganglion cysts are extremely rare in children and only two other cases have been reported previously. They are benign lesions, frequently presenting radiculopathy, and should be considered in the differential diagnosis, in patients with low back pain and radiculopathy.